EL CAJON, Calif. — Federal investigators say the small business jet that crashed near El Cajon Monday evening had recently taken off from Orange County with four people on board.

Firefighters “were not able to find any survivors” after the jet crashed in the unincorporated Bostonia area of El Cajon around 7:15 p.m., the San Diego County Sheriff’s Department said.

As the Federal Aviation Administration and National Transportation Safety Board began their probe into the crash Tuesday morning, they deferred to local authorities for information on the passengers’ identities and whether anyone remained unaccounted for. It is also still unclear what caused the crash.

Initial reports from the federal investigators did shed some new light on the incident, however.

Rick Breitenfeldt, an FAA spokesperson, said the aircraft was a Learjet 35 business jet that had departed John Wayne Airport in Santa Ana and was headed to Gillespie Field Airport in San Diego County with four people on the plane.

“The FAA and NTSB will investigate. The NTSB will be in charge of the investigation and will provide all updates. Neither agency identifies people involved in aircraft accidents,” Breitenfeldt said.

For its part, the NTSB had few details to share on the crash early Tuesday.

“The first NTSB investigator is expected to arrive on scene this morning,” agency spokesperson Peter Knudson said. “Two more investigators will arrive later today. Local authorities will provide information related to the accident victims.”

No one was hurt on the ground but one home was damaged and power lines were knocked down in the area, the sheriff’s department said, causing more than 2,500 San Diego Gas & Electric customers to lose power after the crash. That number had been reduced significantly by early Tuesday.

Roads near the site of the crash, Pepper Drive and North Second Street, remained closed and weren’t expected to reopen until Wednesday.

It remained unclear Tuesday what caused the aircraft to go down. The plane can be seen plummeting downward in Nest surveillance video shared with FOX 5 by a resident. Then a flash of bright light fills the screen.

The crash comes a little over two months after a twin-engine Cessna crashed in another East County community, Santee, where the plane’s pilot and a UPS driver on the ground were both killed. That crash also destroyed two homes and left a couple severely burned. In that case, the small plane had been intended for Montgomery Field.