A firefighter was killed as an electric vault exploded Wednesday afternoon at a business district in Westchester, Los Angeles, authorities said.

Smoke began pouring from the building and there were reports of some explosions so the fire rescue team came to the scene. The dead firefighter was identified as Brent A. Lovrein, 35, a 10-year department veteran.

Lovrein was trying to find out the source of the smoke and what had caused the previous blasts when all of a sudden an electrical vault exploded and killed him. The powerful blast which occurred at the office building at Sepulveda and La Tijera boulevards also wounded another fire fighter and a civilian, officials said.

The injured firefighter was identified as Engineer Anthony J. Guzman. He was taken to the UCLA Medical Center where the staff is treating his fractured arm and broken ankle. The civilian had minor injuries.

The blast occurred at about 2:30 p.m. in the vicinity of Los Angeles International Airport according to Deputy Fire Chief Mario Rueda. The electrical vault exploded just as the firefighters from Station 95 were opening the metal utility door of the equipment.

"We are deeply saddened by what happened today, the loss of one of our family members. These types of incidents hit us very, very deeply," Fire Chief Douglas Barry said.

The blast forced police to seal off the major commercial strip in the area

The utility room from where smoke was pouring contained electric and gas meters connected to an underground electric vault, the LA Department of Water and Power said.

Investigators are still trying to find out what caused the blasts.

"To us, it's not clear where the smoke was coming from and what caused the explosion. But if we had an explosion in the underground vault, it could have caused outages and that did not happen." utility spokesman Joe Ramallo said.

Although the hypothesis that some gas leaks were the cause of the explosion has been was taken in consideration, Fire Department Deputy Chief Mario Rueda said during the news conference that there was no indication, no evidence, that natural gas was involved."