Federal authorities said late Sunday that five people died in a midair collision between two small planes in Southern California, leading to bushfires in the area. A twin-engine Sabreliner jet collided with a single-engine Cessna 172 while they were both on their way to Brown Field Municipal Airport in San Diego County.

Andrew Swick, an investigator for the National Transportation Safety Board (NTSB), reportedly told KNSD-TV, an NBC affiliate, that four people on board the Sabreliner, and the pilot of the Cessna 172, died in the crash, according to the Associated Press (AP). Swick also reportedly said that the pilot of the Cessna was on a cross-country trip, when the incident occurred about 2 miles northeast of the Brown Field airport at about 11 a.m. (2 p.m. EDT).

"It appears that it was a very violent crash as you can tell by both aircrafts that are in multiple pieces," Cal Fire Division Chief Nick Schuler said, according to KNSD-TV, adding: "We don’t know anything about the identities the victims nor where they were taking off or where they were going."

The planes reportedly caught fire after falling to the ground and breaking apart. Initial responders said that the wreckage was spread across a quarter-mile area, AP reported. While the Sabreliner crashed on a grassy slope, the Cessna jet crashed within the boundaries of the San Diego National Wildlife Refuge.

The crash led to a bushfire spreading over a 2-acre area near Route 125 and was soon extinguished before it damaged nearby buildings or structures. Firefighters from the Chula Vista Fire Department responded to the scene and one of them suffered a minor heat-related exhaustion injury, Schuler reportedly said. 

The crashed Sabreliner jet was leased by military contractor BAE Systems, which reportedly said in a statement that some of its employees were on board. Sabreliner jets are generally used by civilians for executive travel and by the military for training. Brown Field is a former naval auxiliary station and is situated in the Otay Mesa area, about 15 miles southeast of San Diego.

The crash is being investigated by the Federal Aviation Administration and NTSB.