Fresno County firefighters arrived at the home on Lolita and Seventh Street around 1 p.m. Sunday. That's when they heard several explosions and saw a fire burning behind the house.
The explosion tore apart a shed and some travel trailers. Initially fire crews thought only one person was hurt. In the end, three people died.
"It was like a big old vibration. Um like if someone was banging on the walls. We thought it was our neighbors' kids. So when we went outside, we saw a bunch of smoke," said witness Lupita Murillo.
That's how witnesses describe an explosion that rattled this Mendota neighborhood around 1:00 Sunday afternoon.
"What did it sound like?"
"Oh, like a bomb," said John Dominguez with Fresno County Cal Fire.
The first call regarding a fire in the back tool shed of a house brought 20 firefighters to the scene. The fire eventually spread to a nearby travel trailer.
Shortly after, a series of explosions went off, creating a dangerous situation for neighbors and fire crews.
"The dangers the firefighters encountered today were life safety hazards with the explosions. They've got to watch out for each other and the other civilians in the area," said John Dominguez with Fresno County Cal Fire.
A helicopter airlifted one person to the hospital, where he died. Fire investigators later discovered the charred remains of two more people as they continued their investigation.
It's unclear what the three victims were doing in the back of the house. Neighbors tell Action News one lived inside the trailer, the other at the house, and the third is from the area.
"Maybe they were just in the wrong place at the wrong time. I'm not sure but its scary cause it makes you think what can happen," said Murillo.
Investigators are still going over evidence from the scene, but say the explosion was not caused by a drug lab. Authorities have not released the names of the victims.