Two people were killed and 18 injured when a small plane crashed through the rooftop of a commercial building in southern California this morning, police said.

Police got a report at 2.09pm local time (9.09am AEDT) about the crash in the Orange County city of Fullerton, said Kristy Wells, a Fullerton police spokesperson.

Firefighters and police arrived on scene and battled a blaze that broke out, and evacuated surrounding businesses, Wells said.

The fire damaged the warehouse, which appeared to contain sewing machines and textile stock. The building was occupied by Michael Nicholas Designs, a furniture upholstery manufacturer, according to a sign on a door.

Ten people were taken to the hospital, while eight were treated and released at the scene, police said. There were two confirmed deaths, according to Wells.

It was not immediately known what type of plane it was or whether those injured were in the aircraft or on the ground, Wells said.

The flight-tracking website FlightAware shows a four-seat, single-engine aircraft crashed about a minute after takeoff.

Security camera footage from Rucci Forge, a wheel manufacturer across the street, shows a fiery explosion and a large plume of black smoke as the plane appeared to dive into the building tilted on its side.

The plane crashed near the Fullerton Municipal Airport, a general aviation airport in Orange County that is about 10km from Disneyland. It has one runway and one heliport. Metrolink, a regional train line, is nearby, and flanks a residential neighborhood and commercial warehouse buildings.

Fullerton is a city of about 140,000 people some 40km south-east of Los Angeles.