Firefighters continued to watch and douse hot spots Tuesday even as arson investigators began probing a blaze that destroyed a seven-story apartment building and damaged two other high-rises in downtown Los Angeles.
Twenty investigators from the Bureau of Alcohol, Tobacco and Firearms are expected Wednesday to join Los Angeles Fire Department and LAPD teams to begin determining the cause of the fire, which is estimated to have caused tens of millions of dollars in damage.
Arson investigators began the task of interviewing those who were the first to respond to the blaze, and some firefighters continued to monitor unburned fuel that remained at the site.
Flames consumed the seven-story, wood-framed structure and radiated enough heat to shatter the windows of office towers on Figueroa Street, reaching inside to melt computers onto desks. The Department of Water and Power reported cracks in at least 160 of its 10-by-4-foot windows.
"A lot of the radiant heat caused a lot of the damage, secondary damage was from the some drifting also, and the water logging from the sprinklers," said David Ortiz of the LA Fire Department.
Caltrans officials said overhead signs on the 110 Freeway were melted and will need to be replaced.
Even as the ignition source remains unknown, there is no question what fueled the ferocity of the flames: five stories of wooden framing sprawling an entire city block.
Like other midrise apartment buildings developed by Geoffrey Palmer, the complex called the DaVinci was designed with concrete and steel for the bottom parking and commercial floors, and wood framing for the residential levels above.
The building code permits a maximum of five levels to be framed in wood, according to Luke Zamperini with the Los Angeles Department of Building and Safety. Taller building requires reinforced concrete or steel framing.
With fire sprinklers and other precautions built into midrise buildings, apartments with wood framing are not considered more vulnerable to fire when completed, but the exposed wood can be a fire hazard during construction.
As a matter of policy, the city of Los Angeles is encouraging highrise development in downtown, according to City Councilman Jose Huizar, who represents the area.
"Not so much because of the safety, but because of the density," Huizar said.
San Francisco launched a review of construction practices after an October fire caused millions of dollars in damage to a commercial building under construction with both wood and steel structural
Prevention is a goal of post-fire followup, said Deputy Chief Joseph Castro, of the Los Angeles Fire Fire Department, who directed the response to the DaVinci blaze. He said changes to the building code could be considered.
All lanes of the Harbor (110) Freeway and transitions roads reopened in downtown Los Angeles Tuesday morning just in time for the morning commute after the massive fire forced closures the day before.