IRWINDALE, Calif. - Four men have died after a second-alarm fire ripped through a commercial building in Irwindale, fire officials said.
Investigators later determined the fire to be "suspicious" in nature.
Los Angeles County fire crews responded to the 400 block of East Arrow Highway, near Live Oak Lane after the fire was reported around 10:35 a.m. Monday.
Images from SkyFOX showed a large plume of smoke that could be seen for miles.
Arriving firefighters called for a second-alarm assignment of additional personnel to be sent to the area. Video from the scene showed flames and smoke shooting through the roof. Crews worked to keep the flames from spreading to other units in the building.
The flames were extinguished at about noon, the county fire department reported.
While checking the inside of the building, firefighters found the charred remains of three men.
A fourth man seen fully engulfed in flames by witnesses was located near the area of the fire and taken to an area hospital, where he succumbed to his injuries.
The names of the four victims have not been released pending next of kin notification.
Investigators said evidence at the scene suggests the warehouse housed a butane honey oil extraction lab.
The cause of the fire was under investigation.
Anyone with information is asked to contact Detective Nicholas Lopez at 626-430-2239. Those who wish to remain anonymous can submit tips to LA Crime Stoppers.