Two people were killed when a stash of fireworks sparked a massive blast in California Tuesday, according to reports and authorities.

Footage of the explosion showed an enormous plume of smoke rising high into the sky in a residential neighborhood of Ontario around 12:30 p.m., according to KABC-TV.

The blast destroyed several buildings and set others on fire. At least two people were dead, the network said.

“I’m just walking. It was like a double boom,” a woman is heard saying on the video.

Police said it was not immediately clear if anyone was hurt in the explosion.

“We are aware of the loud explosion that was heard recently,” officials said on the city’s official Twitter page. “Please stay clear of the area.”

“@OntarioPD and @OntarioFireDept are currently on scene in the area of Fern Avenue and Francis said,” the post said. “A large amount of fireworks at a house ignited, causing a large structure fire. Explosions being heard are by fireworks at this time.”

Video posted online by KESQ-TV shows the aftermath of the explosion, and shows firefighters rescuing a horse from a nearby yard.

CBS Los Angeles also reported that authorities issued an evacuation order for the area and established a temporary care and reception center at a local community center.