A gunman, dressed all in black, stepped on stage in a lecture hall at Northern Illinois University on Thursday and opened fire on a geology class.
A short time later, five students were dead and the gunman had killed himself on the lecture hall stage. Sixteen others were wounded, at least two of them critically.
It was the fifth school shooting in a week in the U.S.
The violence at Northern Illinois unfolded about 3 p.m., as the entry-level ocean sciences class was wrapping up. The gunman -- described as a former graduate student -- stepped out from behind a black curtain on the lecture hall stage, armed with a shotgun and two handguns, police said.
He first shot the instructor, who survived, and then began firing into the seats, filled with at least 100 students, authorities said.
Desiree Smith, 21, was taking notes on continental drift when out of the corner of her eye she saw a figure in a black ski cap step onto the stage, beside the instructor.
"He was holding this huge gun," she said. "I couldn't even process it. He stood there with the gun pointing down, almost like an action-movie poster -- that's what he looked like for a second. Then he lifted it up and shot at my teacher."
Smith dropped to the ground. Under the chair, she locked eyes with another student. They stared at one another in terrified stillness. Then the other student began to move. Afraid of being left alone, Smith followed her, clambering on elbows and knees up the aisle.
"I could feel people bumping me, crawling over me. Everyone was pushing, clawing at the ground, trying to get out as soon as possible," Smith said.
When she got to the door, she could barely make herself stand. "All I could think was, 'I'm gonna die. I'm gonna die. I'm gonna die.' " She forced herself to get up, as shots and screams rang out behind her. "I'm sure I was running really fast, but it felt like slow motion," she said. Only when she had made her way into another building -- into an office, with the door locked behind her -- did Smith realize she had made it out uninjured.
"I kept thanking God, over and over," she said. "I didn't even know what else to do."
John Puterbaugh, a senior, was in the building next door when the first survivors burst in and began barricading themselves in offices.
Puterbaugh, the editor in chief of the campus newspaper, tried to talk to the witnesses; some broke down in tears, shaking, while others recounted the horror in flat, distant tones.
One student in particular, Puterbaugh said, was in such shock that he seemed to be retelling the plot of a movie, "like it wasn't even real to him . . . as if he hadn't just seen a gunman open fire on his class."
Associate Dean W. William Minor saw students pouring out of Cole Hall -- and police arriving en masse, guns drawn -- but could not make sense of the scene.
"I thought someone must have called in a bomb threat," he said.
Within minutes of the shooting police had locked down the campus, posted an alert on the university website about a "possible gunman on campus" and began e-mailing students.
University President John Peters did not release the gunman's name but said he had been enrolled as recently as last spring as a graduate student in sociology at Northern Illinois.
The 25,000-student campus is located in DeKalb, a semirural community about an hour's drive west of Chicago.
"We are surrounded by corn," said Kei Nomaguchi, an assistant professor of sociology. "I am shocked that this happened on our campus."
Another sociology professor, Charles Cappell, said he could not think of any graduate students who had seemed disgruntled or unbalanced.
"We all have incredibly heavy hearts," he said.
Security had been stepped up on the campus in December, after students found menacing graffiti, including racial slurs, in a dorm bathroom. The scrawled note described last year's shooting at Virginia Tech -- which left 32 students and faculty dead -- as unfinished and warned of major changes to come at Northern Illinois.
Peters told a news conference he had "no reason to believe" the graffiti was related to Thursday's shooting, though police will investigate. The graffiti explicitly targeted African Americans; the gunman in Cole Hall appeared to be firing at random.
University Police Chief Donald Grady said the assailant was found dead on the stage. Both of his handguns still had ammunition in them. Gun magazines were scattered across the floor.
Four of his victims were found dead in the lecture hall; the fifth was pronounced dead at a hospital.
Several of the wounded made their way out of the lecture hall as the gunman was firing.
Ben Gross, 22, said he was working at the office of the campus newspaper, the Northern Star, when he heard a "shots fired" bulletin on the police scanner. He raced to Cole Hall -- and then followed a trail of blood about 100 yards to the student center.
In the campus bookstore, he saw a wounded student surrounded by paramedics.
Other victims fled to a nearby dorm, Neptune Hall.
Andrew Patten, a sophomore who had been walking through the area when the shots broke out, followed the wounded into Neptune Hall and treated a student with gunshots to the leg and hand. Someone handed him a first-aid kit, he said; next thing he knew, he was pressing gauze on the wounds and talking to the student about anything he could think of just to keep him conscious. He stayed until paramedics arrived.
"It's still kind of sinking in what actually happened," said Patten, 20.
The shooting followed a string of violence in schools.
Last Friday, a woman shot two students to death and killed herself at Louisiana Technical College in Baton Rouge. Also Friday, a man shot at his wife, a teacher, in an elementary school in Portsmouth, Ohio. This week, a high school student in Memphis, Tenn., was shot, allegedly by a classmate, during gym class. And a 15-year-old was shot at a junior high in Oxnard; he has been declared brain-dead.
In DeKalb, federal and state investigators worked late into the night Thursday, swarming the campus and setting up floodlights around Cole Hall, a two-story, red-brick building.
With midnight approaching, law enforcement officers shot out the window of a white Honda Civic they thought belonged to the gunman and sent a bomb-detecting robot to circle the car. Police dogs were searching the area, which was blanketed in more than a foot of snow.
While some students huddled together in their dorms, or tried to work through the trauma with counselors, Michelle Johansson, 19, said she had to leave campus. She no longer felt safe.
"I'm getting out of here," Johansson said, climbing into her car. "I just want to go home right now."