UPDATED: An explosion in Santa Clarita, Calif. sparked a brush fire, leaving three people critically injured, according to the Associated Press.

Although initial reports said that the explosion was on a film set, the Santa Clarita Valley Signal updated its story on Tuesday night with confirmation from Fire Department spokesperson Jonathan Matheny that the explosion actually occurred at “a business within the industrial park.” The Los Angeles Times also spoke to fire department officials who confirmed it took place at an industrial park and the cause of the explosion is still being investigated.

The Los Angeles County Fire Department did not immediately respond to Variety‘s request for comment.

As reported by the Santa Clarita Valley Signal, the Los Angeles County Fire Department responded to initial reports of an explosion on the 25100 block of Rye Canyon Loop around 4:45 p.m.

Los Angeles County Sheriff’s Deputy Abraham Bedoyan told the Associated Press that the blast was reported in an industrial neighborhood. L.A. County Fire Department Supervisor Martin Rangel said that ambulances took three patients in critical condition to the hospital.

Rangel also told the Associated Press that the fire spread to a hillside, but the flames were quickly put out by firefighters. The L.A. County Fire Department Air Operations Twitter account posted an update at 5:45 p.m., stating that the brush fire had been put out, with additional incident details to follow.

“Three burn victims are all being transported to a local trauma center with additional injuries,” L.A. County Fire Departent Supervisor Ed Pickett told the Signal. “We don’t know what caused it, and we are doing an investigation right now.”

According to the Signal, the location of the explosion is that of the Southern California Innovation Park, which is a listed filming location on the Santa Clarita Film Office website. However, according to the Signal, a representative from the City of Santa Clarita confirmed that there was not a filming permit issued for that location on Tuesday. The Santa Clarita Film Office did not immediately respond to Variety‘s request for comment.