LOS ANGELES — Federal and local investigators tried Tuesday to determine whether an arsonist set a fire that turned an unfinished downtown Los Angeles apartment complex into a block of flames so hot that freeway signs melted and windows cracked in office high-rises as far as a block away.
Crews were dousing hot spots and smoke was billowing more than 24 hours after flames engulfed the wooden frame of the seven-story construction site, leaving a smoldering heap of wood and metal.
The fire that broke out early Monday caused an estimated $10 million in losses to the Da Vinci apartment complex, city fire Capt. Jaime Moore told the Los Angeles Times (http://lat.ms/1wu0xgF ).
Another $1.5 million in damage was done to a freeway where a sign melted and traffic-monitoring fiber-optic cables under the pavement may have to be replaced, authorities said.
Fire officials said they suspect arson because the fire erupted so quickly over so much of the building.
"It's very rare for the entire building to be engulfed at once," Moore said. "There may have been foul play."
City fire investigators and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives will look at surveillance recordings and use dogs that can sniff fire accelerants.
Flames were visible for miles Monday and rained ash onto freeways flanking the construction site. Some signs melted and portions of U.S. 101 and Interstate 110 were shut down as burning debris fell into lanes.
Three floors of a nearby 16-story city-owned building had fire damage and the other floors sustained water damage.
The intense heat also broke glass and melted blinds in three stories of the 15-story Los Angeles County Health Department building.
A block away, the city Department of Water and Power reported cracks in at least 160 of its 10-by-4-foot windows at its headquarters.
The burned apartment complex was planned to be a 1.3 million-square-foot residential building — one of a series of large complexes that have gone up around downtown in recent years.
Shortly after 4 a.m. Monday, another large fire was reported at a mixed-use building undergoing renovations about 2 miles to the west. More than 100 firefighters had the flames under control in less than two hours, Chief Deputy Mario D. Rueda said.
One person in a nearby apartment building was treated for minor smoke inhalation, he said.