Photos: Massive Fire Rips Through Los Angeles Building

Los Angeles city firefighters battle a massive fire at a seven-story downtown apartment complex under construction December 8, 2014. Gene Blevins/Reuters

A massive fire that burned through the construction site of an apartment complex in Los Angeles and damaged nearby buildings Monday morning is being investigated as a "criminal fire."

City arson investigators would "treat it as if it's a criminal fire until proven otherwise," Fire Captain Jamie Moore said, though they could not immediately determine the source of the flames.

Flames spread from a massive fire at the sight of a seven-story downtown apartment complex under construction in Los Angeles, California December 8, 2014. Gene Blevins/Reuters

Over 250 firefighters battled the early morning blaze which shutdown two major freeways, Reuters reports. Firefighters arrived at the scene to find the 1.3 million-square-foot development in flames.

Los Angeles city firefighters battle the fire. Gene Blevins/Reuters

The fire erupted near Harbor Freeway and Hollywood Freeway. Authorities closed a stretch of Harbor Freeway when flames spread across a section of road. They also shut down three off ramps into the area of the fire from Hollywood Freeway.

The blaze destroyed a downtown Los Angeles apartment complex under construction next to a firehouse and damaged three nearby buildings, according to Reuters. Gene Blevins/Reuters

Moore said it was rare for a fire to engulf such a large site so quickly, and even more so because of the lumber damp from recent rains. The size, speed and intensity of the fire led investigators to suspect it might be a "criminal fire."

The fire Monday is being examined by arson investigators as a "criminal fire," authorities said. Gene Blevins/Reuters

The fire spread to a high-rise next door, where it melted telephones, computers, and other office fixtures, and the heat emanating from the flames blew out the windows of other nearby buildings.

The fire stalled commuter traffic for several hours and took three hours to control. Gene Blevins/Reuters

Deputy Chief Joseph Castro said the crews' fast work prevented the fire from spreading farther.

No injuries were reported. Gene Blevins/Reuters

Firefighters remained on the scene after most of the flames had been quelled to do "mop-up work" and pour water on "hot spots that continued to smolder," according to Reuters.

Firefighters stand on lanes of the 110 freeway near smoldering hot spots of a large fire that consumed an apartment building that was under construction. Jonathan Alcorn/Reuters