The huge L.A. fire that engulfed an apartment tower over an area the size of a city block is being treated as a criminal fire.
Although blazes "of this magnitude" are always treated as criminal fires, "it's very rare for the entire building to be engulfed at once," Capt. Jaime Moore told the Los Angeles Times.
"There may have been some foul play."
Arson investigators are going to examine the building and financial records. Dogs trained to sniff out accelerants were also at the scene.
Flames could be seen for miles from the fire that broke out in the DaVinci apartment complex about 1:20 a.m. The fire closed freeways and roads, burst windows of nearby buildings and melted freeway signs.
"It looked like a bomb had just exploded," said L.A. fire Capt. Rick Godinez.
The 110 Freeway northbound was partially reopened at about 10 a.m.
The fire damaged the headquarters of the Los Angeles Department of Water and Power. Intense heat from the blaze cracked at least 160 windows -- each 10 feet high by 4 feet wide.
The department was scrambling to move workers, board windows and provide service to customers. The department warned customers that those dialing for assistance could wait half an hour before anyone answers the phone.
The blaze damaged other nearby buildings, including one that houses city agencies.
"There are windows blown out all the way up the side of our building," said Building and Safety spokesman Luke Zamperini.
More than 250 firefighters battled the blaze at the apartment tower being built on Fremont Avenue downtown, Los Angeles Fire Department spokesman David Ortiz said. The building had 1.3 million square feet of floor space, and officials said two-thirds of it was consumed by flames.
The bulk of the fire was put out in 90 minutes, but firefighters were continuing to deal with hot spots well into the morning, according to LAFD Chief Ralph Terrazas.
There were no injuries reported. The Bureau of Alcohol, Tobacco, Firearms and Explosives was on the scene to help arson investigators determine whether it was intentionally set, said Fire Department spokeswoman Katherine Main.
The fire Monday morning was less than 100 yards away from a downtown fire station.
"When they came out of the quarters they could see it was fully engulfed," Main said. "It was a building under construction in the framing phase. Almost 1 million square feet and a city block."
Firefighters said the flames climbed more than 40 feet above the seven-story building.
The fire at the DaVinci caused damage to at least one of two buildings owned by the city of Los Angeles on Figueroa Street that house government agencies such as building and safety, planning and the Bureau of Engineering. The north tower at 221 N. Figueroa St. experienced fire and water damage, with heat from the blaze shattering windows.
Capt. Steve Tufts oversaw a fire engine that responded to the blaze from an LAFD station on 51st Street in South LA.
"It reminded me of the '80s," Tufts said. "When you got that bare wood. It burns. It burns good."
Tufts' unit helped combat radiant heat in a high-rise next door to the DaVinci that survived the fire. That building was saved, he said, by water from its emergency sprinkler system.
Employees who work at the two burned towers received an e-mail instructing them to report to work elsewhere. Both buildings are "not to be occupied until further notice," the e-mail said.
Terrazas described chaos at the scene of the early-morning fire. Parts of the apartment building scaffolding collapsed and fell over a freeway wall not far from the 101 interchange with the 110 Freeway.
The freeway sign that directed drivers to the interchange was blackened and partially melted, its lettering burned away.
Firefighters used the 110 Freeway to set up equipment to fight the huge blaze.
Caltrans reopened the 101 Freeway and the southbound 110 at around 4:30 a.m.
Many surface streets near the fire were closed as well, further complicating the commute.
A woman in a silver SUV spoke loudly into her cellphone as she pulled into a parking garage off Dewap Road around 6:30 a.m.
"First is shut down and Temple is shut down," she said, sighing. "Downtown is basically shut down."
Another woman carrying a lunch box stopped in front of a police officer blocking a sidewalk near the fire. He let her continue after she explained that she worked nearby.
"Do I still get paid if my building burned down?" she asked, shrugging.
About a dozen construction workers crowded the sidewalk on Figueroa, where the sidewalk leading to Temple Street was blocked.
Edgar Marin, a plumbing worker for GJM Engineering who was working on the DaVinci development, was among those waiting.
The workers watched as fire trucks continued to pass, waiting for the order to head home.
"Probably, if they want, we're going to work tomorrow," Marin said.
A series of dense, upscale apartment complexes have been built over the last decade around the 101-110 interchange in downtown L.A., including the under-construction DaVinci.
Developer Geoffrey Palmer's company is known for the Orsini, the Medici and other faux-Italian apartment buildings that have risen along the four-level interchange. The complexes have been part of the revitalization of downtown, though critics have complained about the design and size of the buildings.
The building was in the news earlier this year when the developer sought a pedestrian bridge that would link the DaVinci to other complexes in the area and offer residents a route to downtown attractions.
The developer told the city that transients living under the 110 Freeway would pose a safety threat to future renters. The bridge proposal faced criticism from some in downtown, but the City Council approved it in May.