A small plane crashed into the Murphy Canyon neighborhood, setting about 15 homes on fire as well as vehicles, and forcing evacuations along several blocks.

A private jet crashed into military housing in San Diego during foggy weather early Thursday, igniting cars parked along a suburban neighborhood block and killing multiple people on board the plane, authorities said.

The plane could hold eight to 10 people but it’s not yet known how many were on the aircraft, Assistant San Diego Fire Chief Dan Eddy said at a news conference. Authorities will be investigating whether the plane hit a power line, he said.

The aircraft crashed just before 4 a.m. into the U.S. military’s largest housing neighborhood. It appeared to strike at least one home that had a charred and collapsed roof and smash through half a dozen vehicles. About 10 homes suffered damage.