EL MONTE, Calif. (KABC) -- A man was killed and 12 people were displaced from their homes after a fire broke out overnight at an apartment complex in El Monte.
The fire was reported at 3:12 a.m. at the 4-unit apartment building near Magnolia Boulevard and Peck Road. Investigators said firearms and ammunition were found in the victim's second floor apartment.
"There were popping noises going off in the upstairs unit, there was several firearms and ammunition found," said Battalion Chief Frank Garrido of the Los Angeles County Fire Department. "In a fire situation, the ammunition ... it pops really with no velocity but there is still danger to those rounds going off to the fire."
Resident said they heard what sounded like explosions coming from the building.
"I heard some glass shattering, just falling off," said one of the residents. "So when I heard that, I was thinking, 'Okay, so my window just broke because there has been an earthquake going on.'"
The fire reportedly began in the vicinity where the victim's body was located. The El Monte Police Department said the victim, who has been identified, lived alone.
The building was red-tagged and marked "unsafe" by Monday afternoon, forcing 12 people to seek shelter, including Juan Jacinto and his family.
Jacinto said he feared for his life when he saw the blaze take over the building.
"I opened the door and looked upstairs to the window and it was exploding like fireworks," he said. "I went in to get my kids."
Meanwhile, the exact cause of the fire remains under investigation. Detectives are examining the firearms, hoping to track down the owner.
Some neighbors told ABC7 they didn't know the man who died, but described him as an older man.
"He didn't talk to us, to nobody. He was reserved," said Jacinto.
The American Red Cross is helping those who were displaced. Anyone with information on the fire is urged to contact police.