A F-16 fighter plane returning to March Air Reserve Base in Moreno Valley crashed after its pilot ejected, base officials said on Thursday.
The Air National Guard jet was carrying a "standard armament" package, Col. Thomas McNamara, vice commander of the Air Force Reserve's 452nd Air Mobility Wing at March Air Reserve Base, said at a news conference.
The pilot managed to eject from the aircraft and was receiving medical treatment, according to the Riverside County Sheriff's Department. "The pilot did eject and the pilot is okay", he added.
"I turned around, and my co-worker just told me to get, so I just made a run for it". It is not known if the five people from the deputy fire chief's report were included, or in addition to the twelve people described by Capt. Fernando Herrera.
According to KTTV-TV, no fatalities were reported stemming from the crash.
The pilot, who was the only person on board, was taken to a hospital for examination, officials said.
Images from the scene show a gaping hole left in the roof of a warehouse.
Local outlet NBC Los Angles reported that the fighter jet had "pancaked" onto the roof of the warehouse.
"The pilot was having hydraulic problems", Holliday told the AP. "He started losing control of the aircraft".
Live video from a news helicopter shows the jet's canopy laying on the overrun of the runway and a parachute and harness nearby.
Damage to the warehouse was relatively minor, and there was no major fire, which Mr Holliday said was "a miracle".
The F-16 was on a training mission under the direction of the North American Aerospace Defense Command.
The unit flying this alert mission from the base in Riverside, California, was a combination of pilots and aircraft from California and South Dakota Air National Guard units.
Fighter jets are a rarity at March Air Reserve, which is home to the 452nd Air Mobility Wing, an Air Force Reserve which uses the huge C-17 transports, KC-135 refueling tankers and C-130 transports.