As a horrified nation watched on television, the twin towers of the World Trade Center in lower Manhattan collapsed into flaming rubble after two Boeing 767s rammed their upper stories. A third airliner, a Boeing 757, flattened one of the Pentagon's five sides.
A fourth jetliner crashed in western Pennsylvania. Authorities said the hijackers might have been trying to aim the plane at the presidential retreat at Camp David, Md., the Capitol or other targets in Washington.
PHOTOS: The attacks of September, 11, 2001
The assaults, which stirred fear and anxiety across the country and evoked comparisons to Pearl Harbor, were carefully planned and coordinated, occurring within 50 minutes. No one claimed responsibility, but official suspicion quickly fell on Saudi fugitive Osama bin Laden. Unexplained was how the terrorists boarded the jets and overpowered the crews.
Federal law enforcement sources said the FBI conducted searches and served subpoenas, some in south Florida. One official said agents were investigating the possibility that some of the terrorists were pilots who had been trained "for this kind of action."
The FBI was sifting through hundreds of tips pouring into a toll-free hotline and a Web site and pursuing dozens of leads.
Addressing the nation Tuesday night, President Bush vowed to "find those responsible and bring them to justice." This country, he said, would retaliate against "those behind these evil acts" and any country that harbors them.
Altogether, the four downed planes carried 266 people. All were killed. Scores of people jumped to their deaths or died in fires and the collapsing superstructure at the Trade Center. New York Mayor Rudolph W. Giuliani said earliest reports counted 2,100 people injured, about 150 of them in critical condition.
Estimates of the death toll at the Pentagon ranged from 100 to 800.
At nightfall, more than nine hours after the attack, a 47-story annex to the 110-floor twin towers at the Trade Center collapsed as well. It too had caught fire, but by the time it fell, all of its occupants had been evacuated.
At a late-night news conference, New York authorities said more than 300 firefighters and three dozen police officers were missing. Many had rushed into the towers after the airliners hit, only to be trapped when the buildings collapsed.
Among the dead were the New York fire chief, his chief of special operations and a first deputy commissioner.
Some of those still in the rubble reportedly called officials or family members on their cell phones, and some trapped police officers made radio contact with headquarters. But because of fires and unstable debris, rescue attempts were halted after dark.
Bush placed U.S. forces around the world on highest alert and flew from a visit in Florida to secure military bases in Louisiana and Nebraska before returning to Washington to address the nation. Vice President Dick Cheney, Cabinet members, congressional leaders, and the president's family also were taken to secure locations.
It was the worst siege of terrorism waged against the United States in its history. It shut down the federal government in Washington and the financial markets in New York. It closed all airports across the nation for the first time, as well as some Amtrak rail lines in the Northeast. It put off the primary election in New York and closed Disneyland. It halted major league baseball for a day, as only World War I and D-day have done before.
America tightened security at its borders and at embassies and military sites around the world. The National Guard patrolled Washington and New York. Bridges and tunnels into Manhattan were closed. Authorities evacuated the Capitol Building, the State Department, the CIA building, the United Nations and the Sears Tower in Chicago. Hoover Dam was closed to visitors. Patrols increased along the trans-Alaska oil pipeline.
Even in Europe, authorities evacuated high-rise buildings as a precaution.
Members of Congress, after being briefed by FBI and intelligence officials, said Bin Laden was the suspected mastermind. "They've come to the conclusion," said Sen. Orrin G. Hatch (R-Utah), "that this has the signature of Osama bin Laden." He is the fugitive Saudi terrorist under indictment here for the bombing of American embassies in Kenya and Tanzania. Bin Laden has been granted asylum by Afghanistan.
That nation's hard-line Islamic Taliban rulers condemned the attacks in New York and Washington and rejected suggestions that Bin Laden was behind them. In London, editor Abdel-Bari Atwan of the Al-Quds al-Arabi newspaper said he had heard that Islamic fundamentalists close to Bin Laden were planning a major operation but that he did not take the threat seriously.
"They said it would be a huge and unprecedented attack," Atwan told Associated Press, "but they did not specify."
Anger across the United States brought talk of retaliation. "These attacks clearly constitute an act of war," said Sen. John McCain (R-Ariz.).
He was echoed by Adm. Robert J. Natter, commander of the U.S. Atlantic Fleet. "We've been attacked like we haven't [been] since Pearl Harbor."
"This is the second Pearl Harbor," said Sen. Charles Hagel (R-Neb.). "I don't think I overstate it." Nearly 2,400 people died when the Japanese attacked Pearl Harbor on Dec. 7, 1941. It drew the United States into World War II.
Governments around the world offered condolences and pledged solidarity in the fight against terrorism. Palestinian leader Yasser Arafat said he was horrified by the attacks. But in the West Bank town of Nablus, about 3,000 people took to the streets, chanted "God is great" and handed out candy in a gesture of celebration.
Russian President Vladimir V. Putin called the attacks "terrible tragedies." China said it was "horrified." Pope John Paul II condemned the "unspeakable horror" and prayed for the victims and their families.
The sequence of events that stunned New York into grief-stricken agony began at 7:59 a.m. EDT, when American Airlines Flight 11 took off from Boston's Logan International Airport. The flight carried 81 passengers and a crew of 11 westward toward Los Angeles International Airport. Fifteen minutes later, United Airlines Flight 175 left Logan, also bound for Los Angeles. It carried 56 passengers and a crew of nine.
What transpired inside both aircraft in the minutes that followed remains unclear; it never may be known. Later in the day, however, federal authorities would speculate that the planes were chosen by their hijackers because their transcontinental loads of jet fuel effectively made them flying bombs.
Atty. Gen. John Ashcroft said the hijackers of Flight 11 were armed with knives. Other reports indicated some flight attendants on Flight 175 were stabbed.
A Routine Start to Day and Then Chaos
What is known for certain is that Flight 11--the first aircraft to strike the World Trade Center--was hijacked somewhere over upstate New York, made a hard left turn and flew for approximately 14 minutes until it struck the Manhattan landmark.
Flight Explorer, a Virginia-based company that sells Federal Aviation Administration radar data to airlines, was tracking the flight. According to Walter Kross, one of the company's technical specialists, the 767 was flying at 29,000 feet near Albany, N.Y., when it veered to the southeast.
The plane's speed dropped from about 450 knots to 340 knots. The Boeing 767 flew faster as it headed for the New York area, reaching a speed of 500 knots. It then slowed to about 300 knots as it approached the World Trade Center.
About 8:30 a.m., it slammed into the building.
"It had to have been hand-flown," Kross said, suggesting that at least one of the hijackers was skilled enough to pilot the aircraft with precision.
A thunderstorm Monday night had cleared the air over Manhattan and the sunlight of a warm September morning was glinting off the Hudson River as the business day began in the city's highest buildings.
Clyde Ebanks, vice president of an insurance company, was at a meeting on the 103rd floor of the World Trade Center's south tower when his boss said, "Look at that!"
He turned and saw a plane go past and hit the north tower.
Carnage and chaos ensued.
Peter Dicerbo led his 44 colleagues from the First Union National Bank down 47 flights of stairs. He staggered away from the building, his clothes torn; the workers were stunned, dazed and coughing.
Less than 20 minutes later, the United Airlines jet struck the other World Trade Center tower.
"The minute I got out of the building, the second building blew up," said Jennifer Brickhouse, 34, from Union, N.J., who was riding an escalator into the trade center when she "heard this big boom."
"All this stuff started falling," she said, "and all this smoke was coming through. People were screaming, falling and jumping out of the windows."
At least one couple were seen leaping hand-in-hand from the tower's upper stories.
Three miles away, across the East River in Brooklyn, sheets of office paper fluttered out of the sky.
At 9:50 a.m., an hour after the first crash, the first World Trade Center tower collapsed in smoke and rubble.
There were reports of an explosion right before the tower fell, then a strange sucking sound, and finally the sound of floors collapsing. Then came a huge surge of air, followed by a vast cloud of dirt, smoke, dust, paper and debris. Windows shattered. People screamed and dived for cover.
"I heard the largest, loudest collective scream I've ever heard," said Melissa Easton, who was watching from the roof of her Chinatown apartment building about 20 blocks away.
Not long afterward, at 10:30 a.m., the second tower of the World Trade Center collapsed.
The top of the building exploded with smoke and dust. There were no flames, just an explosion of debris, and then more vast clouds swept down to the streets. People were knocked to the ground on their faces as they ran from the building.
Hyman Brown, a University of Colorado civil engineering professor and the construction manager for the World Trade Center, said that flames fueled by thousands of gallons of aviation fuel melted the towers' steel supports.
"This building would have stood had a plane or a force caused by a plane smashed into it," he said. "But steel melts, and 24,000 gallons of aviation fluid melted the steel. Nothing is designed or will be designed to withstand that fire."
In addition to the more than 200 missing firefighters, police officials said nearly 100 of their officers were similarly unaccounted for. Brian Stark, a former Navy paramedic who assisted rescuers, said paramedics had been told that hundreds of police officers and firefighters were missing from the ranks of those sent in to respond to the first crash.
Giuliani said the 2,100 injured included 1,500 "walking wounded" who were taken by boat to New Jersey, and 600 others who were taken to New York hospitals. It could take weeks to dig through the rubble for victims. "I have a sense it's a horrendous number of lives lost," Giuliani said. "Right now we have to focus on saving as many lives as possible."
Hundreds of volunteers and medical workers converged on triage centers, offering help and blood. So many people lined up to donate blood that many were turned away.
The city took on the eerie hush of a metropolis under siege. With public transportation shut down and major bridges and tunnels closed to traffic, walking became the only way to get anywhere. Thousands clogged Manhattan bridges, leaving the city on foot. Throughout the metropolitan area, people stunned by the day's events strolled about as if in a daze.
More than nine hours after the attack, an annex in the complex--7 World Trade Center--continued to burn. At 5:20 p.m., that building collapsed. Blocks away, crowds roared with astonishment.
"People stared open-mouthed and were in shock," said bystander Russ Baker.
Jesus Soriano Jr., 34, of Brooklyn, said he was there when the twin towers fell.
"I felt the first building collapse. I saw the second tower collapse," Soriano said. "It collapsed from the outside in."
"Those terrorists are real cowards," he said.
Tyler Catalana, 23, a resident of Mill Valley, Calif., who is studying architecture in New York, said he saw the north tower collapse into itself.
"It looked like a nuclear war," he said.
Catalana said that when the dust began to settle, "it looked like the surface of the moon."
Much of lower Manhattan was evacuated as officials feared potential gas leaks and falling debris could cause further casualties.
Like refugees fleeing a war-town nation, tens of thousands walked across the Brooklyn Bridge and along a nearby highway as they sought safety.
Some people wore paper masks to block out the dust. People gathered around cars listening to news over their radios. Others washed off the dust with the water from open fire hydrants.
Giuliani said the New York Stock Exchange was intact, but he doubted it would reopen today, because it was necessary to keep lower Manhattan clear for emergency vehicles. Public and parochial schools in the city were scheduled to be closed.
"New York is still here. The World Financial Center is still here," the mayor said. "We have undergone tremendous losses and we will grieve for them horribly. We are going to prevail."
Three large trucks arrived at the city morgue in the afternoon with extra supplies. A spokesman said that bodies were expected later.
Families searching for missing relatives were directed to an office where city employees took information. Extra medical examiners were summoned to the morgue.
The most severely burned were taken to a center at New York Presbyterian Hospital on Manhattan's upper East Side. Elective surgery at the hospital was canceled. Patients in the emergency room watched the disaster on television.
Tiffany Keeling, 32, of New Mexico was treated at Bellevue Hospital for smoke inhalation and head injuries. She said she was attending a training seminar for financial consultants on the 61st floor of the south tower of the trade center.
"We were looking out the window and the entire sky was filled with paper," she said. "We thought it was a ticker tape parade."
Then, Keeling said, she noticed a huge cloud of smoke billowing from the north tower. "Fireballs were falling to the ground, which I now know were people."
Keeling and the other trainees headed for the stairs. When they were between the 59th and 58th floors, a voice on the building's public address system said the north tower was the only structure in danger and that everyone could return upstairs. Half of her group went back up. She and others continued to the street.
"People were coming down from the top floors in every condition you could imagine," Keeling said, through tears.
"I heard a woosh like air getting sucked in a vacuum. I grabbed my jacket and got as close to a planter as possible and started feeling little things on my back like hail, and they got bigger and bigger until the air was solid debris."
Keeling said she turned to a man who walked down the stairs with her and asked: "Are we dead?"
She said only 75 of the people who attended her training group were accounted for.
Denny Levy, 36, a videographer, witnessed the impact from the ground.
"I saw this plane flying low over the buildings down the center of Manhattan," said Levy, who was uninjured. "It went toward the World Trade Center. It sounded like its engine was broken. Your brain tricks you. I thought it went past the building, and then it went a little to the left and took a plunge at the building.
"Then there was this burst of stuff coming out of the building. There was no fire and no explosion. I wondered why the plane was making so much noise and was so low.
"You could tell it was a passenger plane, that it was in trouble or trying to get close for a view. You'd never think a plane would go dead center into a building. It was like a missile.
"I thought it was an accident, except he took a sudden left. He went right for it. It was so creepy. I thought, 'Oh my God, I just saw 300 people die.' "
John Kelly, 38, a furniture designer, said he looked out a window of his apartment after hearing the first explosion.
"My wife says, 'Oh, my God, they hit the second building.' I looked. The plane went through the building, and there was a blast out two sides. It was like exit wounds in all directions.
"I saw people jumping, bodies flying through the air. I saw people waving white flags. It was horrible.
"Police and ambulances were everywhere, and within seconds there was no one. You saw everyone running, running, running. You saw shoes, sunglasses on the street. People dropped their stuff and ran.
"It was like a nuclear explosion."
A Crushing Blow to Symbol of Strength
As a stunned nation attempted to grasp the horror of television images from New York, a third hijacked airliner crashed into the Pentagon, bursting into flames and delivering an incendiary blow to the symbol of America's military might.
American Airlines Flight 77, a Boeing 757 with 58 passengers and a crew of six aboard, hit the west side of the building at 9:41 a.m. EDT, half an hour after it left Dulles International Airport en route to Los Angeles.
"I glanced up just at the point where the plane was going into the building," said Carla Thompson, who works in an Arlington, Va., office building about 1,000 yards from the crash.
"I saw an indentation in the building and then it was just blown-up up--red, everything red," she said. "Everybody was just starting to go crazy. I was petrified."
Within 20 minutes of the crash, the White House, the Pentagon--the world's largest office building--and the U.S. Capitol were evacuated.
What began as an orderly exodus from the nation's defense headquarters turned to panic as evacuees made their way to parking lots.
"People were just milling around in a daze," said Ginger Groeber, a civilian Defense Department official who had been in the Pentagon watching television reports of the attacks in New York when the building was hit.
"These people were panicking out there," she said. "People were looking for their staffs. Nobody's cell phones were working."
The District of Columbia government shut down. Many private firms also closed and sent employees streaming home, causing traffic nightmares.
As parking garages closed and cars poured out, one woman grabbed the door of a lone car going in.
"Don't park," she yelled, her face twisted in fear. "They're hitting the Pentagon! They're hitting the Pentagon!"
Naval officer Clyde Ragland, who works near the Pentagon, was stuck in his office because the streets outside were clogged with traffic.
He and his co-workers were watching television reports of the disaster in New York when "we gazed out our own windows and, to our horror and disbelief, saw huge billows of black smoke rising from the northeast, in the direction of D.C. and the river . . . and the Pentagon."
Ragland described billowing black smoke and "what looked like white confetti raining down everywhere." He said it soon became apparent "that the 'confetti' was little bits of airplane, falling down after being flung high into the bright, blue sky."
"Everything is confusion right now, but there was no panic. Just stunned disbelief," Ragland said.
Streets surrounding the Capitol Mall were paralyzed as people tried to get away from the federal buildings, worried that they would be targeted next.
Federal workers raced down the steps into the subway, only to be greeted by a sign flashing: "Security alert! The Metro is closed until further notice. Please try to call a relative or a taxi if you need a ride." The subway reopened by midday.
But with phone lines jammed and no taxis to be found, many people tried to hurry away on foot, exchanging rumors about the attacks.
"We never thought this could happen," said Mary Shea, 58, an FAA program analyst, as she stood outside the L'Enfant Plaza subway stop. "What a shock, what a shock."
Long lines formed around pay phones.
"My mom works at the Pentagon, my mom works at the Pentagon," one man repeated over and over again, rocking back and forth, urging the line to speed up.
Abigail Harrington, an employee at the District of Columbia Department of Health, stood with a large group of people on 7th Street, peering down the road for a bus she hoped to catch to pick up her daughter from school.
"I feel horrible," said Harrington, clutching her hands together. "I can't reach my husband on his cell phone. I don't know what's going on. You never think that something like this can affect the world's biggest superpower. It's really, really scary. It really is."
Secretary of Defense Donald H. Rumsfeld was in a wing of the Pentagon opposite the point of impact. He told reporters that he felt the shock and went outside where volunteers were helping to carry away the injured.
Rumsfeld refused to estimate the casualty toll at the military's nerve center. The plane crashed into a newly renovated portion of the building that had not been fully reoccupied.
Authorities estimate that 23,000 people work in the Pentagon, and Rumsfeld vowed that the building would reopen for business today.
Barbara Olson, the wife of U.S. Solicitor General Theodore B. Olson, spoke to her husband twice by cell phone from the hijacked airliner before it crashed.
She told him that all the passengers and crew, including the pilot, were forced to the back of the plane. The only weapons she mentioned were knives and cardboard cutters.
Olson said his wife made no reference to the nationality or motive of the hijackers.
Barbara Olson had originally planned to take a Monday flight to Los Angeles but changed her plans to have breakfast with her husband Tuesday, his birthday.
The plane that crashed in Pennsylvania, United Airlines Flight 93, took off at 8:01 a.m. EDT from New Jersey's Newark International Airport, bound for San Francisco. On board the Boeing 757 were 38 passengers, two pilots and five flight attendants. The early stages of the flight seemed normal, with the plane charting a westerly course that brought it to northern Ohio.
But as the jet was flying due west just below Cleveland, it made a sharp U-turn. Radar tracked it passing just south of Pittsburgh.
At 9:58 a.m., a 911 operator in Pennsylvania's Westmoreland County received a call from a man who said he had locked himself in a bathroom on a hijacked airliner. "We are being hijacked, we are being hijacked," the man said over his cell phone.
At the same time, flight attendant CeeCee Lyles, a mother of four, dialed her cell phone and told her husband, a Fort Myers, Fla., policeman, that her flight was being taken over by hijackers.
The Westmoreland County dispatcher, Edward Milliron, said his office was taking information from the passenger in the bathroom when the line went dead.
"We lost them," he said. "Two or three minutes later, we lost them."
Milliron said area residents began calling to report that a passenger jet was flying low over their homes. The plane crashed at 10:06 a.m. in a rural area near Indian Lake, about 80 miles southeast of Pittsburgh.
"I felt it. My house was shaken by it. I thought a truck hit my house," said Rev. Sylvia Baker, who lives about two miles from the crash site. "When I saw it wasn't my house, I was sure it had to be my neighbor's house."
The plane went down in an open field near a coal strip mine outside Shanksville, a hamlet of 235 people nestled in the wooded hills of western Pennsylvania. Mark Stahl of nearby Somerset said it carved a large black hole in the field and that smoke and flames billowed out.
"I didn't know what to think. It was shocking," Stahl said.
Reporters said the crater was about 40 feet wide and more than 8 feet deep. The largest debris from the plane was no bigger than a phone book. The crater was cordoned off, and officials said the task of removing bodies and the debris would not begin until this afternoon.
After a briefing by the Marine Corps, Rep. James P. Moran (D-Va.) said the plane may have been turning toward Camp David or Washington targets in its flight path when it went down. The crash site was 85 miles northwest of Camp David in the mountains of Maryland.
Response to the tragedies came from a number of quarters, some calling for swift retaliation while others urged moving ahead cautiously.
Former Secretary of State James A. Baker III said the United States should strengthen its intelligence capabilities.
"In effect, we unilaterally disarmed our intelligence capabilities," Baker said. "We need human intelligence to penetrate these groups."
Richard Holbrooke, former U.S. ambassador to the United Nations, said it would take the cooperation of numerous countries, including Russia and states in the Middle East, to bring those responsible to justice.
"Any nation seen to harbor or aid and abet these people must be treated as co-equally responsible," he said.
Larry Johnson, a former State Department counter-terrorism official, said the United States must wage war against those who launched the attacks.
"This is a declaration of war," Johnson said. "You don't go in for a tie here. If these guys want to cross the line this way, so be it. But so will we. We can't go back now. If we don't act, the U.S. will be seen as unable to fight."
But John L. Martin, the former chief of the internal security section at the Department of Justice, urged restraint.
"Any kind of retaliation must be very restrained, and methodical, deliberate and accurate," Martin said. "Or else it's going to worsen the situation."
Rep. Dana Rohrabacher (R-Huntington Beach) called the attacks a "day of infamy" for the nation's intelligence community.
"For the national security apparatus to have missed this is the biggest intelligence blunder in our lifetime," Rohrabacher said. "The people we pay billions of dollars to have left us at the mercy" of international terrorists."
Brian Jenkins, a Rand Corp. expert on terrorism and international crime, said in Santa Monica: "We've seen elements of this event before. Thirty years ago, almost to the day, Sept. 6, 1970, four hijackings, one of which failed, involved the Popular Front for the Liberation of Palestine, who held hostages in the desert outside Jordan. It was a multiple coordinated hijacking.
"And we've had concerns that hijackers might crash into a major city. Algerian extremists in Marseilles [in] 1994 wanted refueling. French Intelligence, listening, feared they would take off and crash into Paris.
"Today, versus 30 years ago, the acts are large scale and often indiscriminate. The World Trade Center event today combines the two."
At UCLA, David Rapoport, editor of Terrorism and Political Violence, an academic journal, said there has been nothing like today's attack "in the history of terrorism."
Rapoport said the attack required "extensive planning by numerous individuals."
"The organization capable of this act has managed to elude our intelligence. We were not looking at the right organizations. And if we were, our failure is even greater."
Contributing to this report were Times staff writers Ricardo Alonso-Zaldivar, Geraldine Baum, Stephen Braun, Richard T. Cooper, Megan Garvey, Judy Pasternak, David G. Savage, Esther Schrader, David Willman, Robin Wright and Aaron Zitner in Washington; John J. Goldman and Thomas S. Mulligan in New York; Eric Slater in Chicago; Edward J. Boyer, Richard Lee Colvin, Thomas Curwen, Abigail Goldman, Ardith Hilliard, J. Michael Kennedy, Jeff Leeds, Hilary E. MacGregor, Eric Malnic, Richard E. Meyer, Diane Pucin, Mary Rourke, Tim Rutten, Henry Weinstein and Nona Yates in Los Angeles.