Downtown Los Angeles fire

A staircase to nowhere sits by itself after a massive fire in downtown Los Angeles early Dec. 8 leveled an apartment tower under construction.  (Al Seib / Los Angeles Times)

Arson investigators from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives on scene to conduct an investigation into December’s Da Vinci apartment complex fire.  (Barbara Davidson / Los Angeles Times)

An elevated view of all that is left of the 1.3 million-square-foot Da Vinci apartment complex that was destroyed by fire in December.  (Barbara Davidson / Los Angeles Times)

Traffic flows along the 110 Freeway in downtown Los Angeles next to the remains of what was to be the Da Vinci apartment complex that was destroyed by fire in December.  (Barbara Davidson / Los Angeles Times)

A massive fire engulfs a apartment building construction site near downtown Los Angeles on Dec. 8.  (Nancy Yuille / Associated Press)

A crane begins to tear down the seven-story Da Vinci apartment complex.  (Barbara Davidson / Los Angeles Times)

The smoldering ruins of the Da Vinici building.  (Barbara Davidson / Los Angeles Times)

Work crews walk past a still-smoldering construction site after it was destroyed in an early morning fire.  (Barbara Davidson / Los Angeles Times)

Investigators outside a building that was partially destroyed in an early morning fire next to the 110 Freeway.  (Barbara Davidson / Los Angeles Times)

Arson investigators survey the scene after a massive fire in downtown Los Angeles.  (Al Seib / Los Angeles Times)

Caltrans workers remove signs over the 110 Freeway after a massive fire at a nearby apartment complex project on Dec. 8.  (Patrick T. Fallon / For The Times)

A firefighter hoses down hot spots after battling a massive fire at the Da Vinci apartment complex under construction on Temple Street and Fremont Avenue in downtown Los Angeles on Dec. 8.  (Patrick T. Fallon / For The Times)

Arson investigators and an ATF agent, center, walk along the 110 Freeway near the site of the blaze on Dec. 8.   (Al Seib / Los Angeles Times)

Firefighters spray water on hot spots after a massive fire in downtown Los Angeles in December.  (Al Seib / Los Angeles Times)

The extreme heat from the fire melted a nearby parking sign.  (Al Seib / Los Angeles Times)

Firefighters look out from the shattered windows of a nearby office building damaged by the morning blaze. 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.  (Al Seib / Los Angeles Times)

A firefighter looks at the twisted metal that used to be scaffolding surrounding an apartment complex under construction brought down by a massive fire in downtown Los Angeles early Dec. 8.  (Al Seib / Los Angeles Times)

A burnt palm tree is all that if left standing after a massive fire in downtown Los Angeles in December.  (Al Seib / Los Angeles Times)

As freeway traffic passes by, smoke rises from the scene of a massive fire at the Da Vinci apartment complex project in downtown Los Angeles on Dec. 8.  (Patrick T. Fallon / For The Times)

Blown-out windows are seen on the Lewis Brisbois Building on Dec. 8 as smoke lingers after a massive fire at a nearby apartment complex project in downtown Los Angeles.  (Patrick T. Fallon / For The Times)

Firefighters stand on the 110 Freeway on Dec. 8 after battling a massive fire at the nearby Da Vinci apartment complex under construction on Temple Street and Fremont Avenue in downtown Los Angeles.  (Patrick T. Fallon / For The Times)

Firefighters tackle the remnants of a massive fire at the Da Vinci apartment complex project downtown Los Angeles on Dec. 8.  (Patrick T. Fallon / For The Times)

A stairwell is all that remains standing Dec. 8 as firefighters work on subduing a blaze at an apartment complex project in downtown Los Angeles.  (Patrick T. Fallon / For The Times)

Firefighters battle a blaze at a construction site on 7th street near MacArthur Park in Los Angeles on Dec. 8.  (Patrick T. Fallon / For The Times)

Firefighters tackle a fire at a construction site on 7th street near MacArthur Park in Los Angeles on Dec. 8.  (Patrick T. Fallon / For The Times)

CalTrans crews begin the clean up process on the 110 Freeway after a massive fire that engulfed an apartment tower under construction left freeways signs damaged and debris scattered across lanes.   (Al Seib / Los Angeles Times)

Parts of scaffolding are all that is left standing after a massive fire in downtown Los Angeles.  (Al Seib / Los Angeles Times)

Parts of scaffolding are all that is left standing after a massive fire in downtown Los Angeles engulfed an apartment tower under construction.  (Al Seib / Los Angeles Times)

Firefighters hose down hot spots after battling a massive fire in downtown Los Angeles on Dec. 8.  (Al Seib / Los Angeles Times)

Smoke lingers on Dec. 8 after a massive fire in downtown Los Angeles engulfed an apartment tower under construction.  (Patrick T. Fallon / For the Times)

Firefighters spray water on the remnants of a structure fire in downtown Los Angeles. The building was completely destroyed and the intense heat heavily damaged two nearby buildings while also forcing the closure of Interstate 110.  (PAUL BUCK / EPA)

Los Angeles County firefighters battle a fire at an apartment building under construction next to the 110 Freeway in Los Angeles.  (Damian Dovarganes / Associated Press)

Los Angeles County firefighters battle a fire at an apartment building under construction next to the 110 Freeway in Los Angeles.  (Damian Dovarganes / Associated Press)

Los Angeles County firefighters battle a fire at an apartment building under construction next to the 110 Freeway in Los Angeles.  (Damian Dovarganes / Associated Press)

Los Angeles County firefighters battle a fire at an apartment building under construction next to the 110 Freeway in Los Angeles.  (Damian Dovarganes / Associated Press)

Firefighters work to put out flames at an apartment complex under construction in downtown Los Angeles on Dec. 8.   (Patrick T. Fallon / Los Angeles Times)

A fire lights the night sky near the 110 and 101 freeways in downtown Los Angeles on Dec. 8.   (Damian Dovarganes / Associated Press)

Firefighters deal with heavy smokes as they battle a blaze in the 900 block of Fremont Avenue in downtown Los Angeles on Dec. 8.  (Patrick J. Fallon / Los Angeles Times)