Assistant Fire Department Chief Dan Eddy said said “there is a direct hit to multiple homes” in the Murphy Canyon neighbourhood of San Diego early on Thursday morning (Thursday night AEST).

“We have jet fuel all over the place,” he said, during a news conference.

“Our main goal is to search all these homes and get everybody out right now.”

He described “a gigantic debris field” in a dense, packed neighbourhood where a number of military families live.

It was not known if there were any injuries.

On the street, one home’s roof was blackened and collapsed, with a piece of white metal sitting on the street in front.

Half a dozen fully charred cars sat on the street and tree limbs, glass and pieces of white and blue metal were scattered on the road. At the end of the street black smoke billowed as the site continued to burn.

Christopher Moore, who lives one street over from the crash site, said he and his wife were awakened by a loud bang and saw smoke when they looked out the window.

They grabbed their two young children and ran out of the house. On their way out of the neighbourhood they saw a car engulfed in flames.

“It was definitely horrifying for sure, but sometimes you’ve just got to drop your head and get to safety,” he said.

Many military service members live in the neighbourhood, which is made up of single family homes and townhouses. It also is heavily populated by small civilian and military aircraft.

Marine Corps Air Station Miramar, Montgomery-Gibbs Executive Airport and Gillespie Field are nearby.

Eddy said it was very foggy at the time the private plane crashed.

“You could barely see in front of you,” he said.

The Cessna 550 aircraft crashed about 3.45am (8.45pm AEST) near the Montgomery-Gibbs Executive Airport, the Federal Aviation Administration said.

“The number of people on board is unknown at this time,” the FAA said in a statement.

The plane can carry six to eight people.

The FAA said the National Transportation Safety Board will lead the investigation.

In October 2021, a twin-engine plane plowed into a San Diego suburb, killing the pilot and a UPS delivery driver on the ground and burning homes. It was preparing to land at the airport.

In December 2008, a Marine Corps fighter jet slammed into a house in San Diego’s University City neighborhood, causing an explosion that killed four people inside. The Marine Corps blamed the crash on mechanical failure and human error.