A vintage biplane has crashed, killing the 77-year-old pilot, while performing a stunt at a California air show attended by thousands of people.
The San Francisco Chronicle reports that the Stearman biplane crashed in an open field away from the estimated 100,000 spectators. Black smoke rose from the wreckage as crowds were evacuated.
Lynn Lunsford of the Federal Aviation Administration said emergency responders said the pilot did not survive.
An Air Force statement identified Edward Andreini as the pilot of the 1944 plane.
Colonel David Mott, 60th Operations Group commander at Travis Air Force Base, said the plane was trying to perform a manoeuvre known as "cutting a ribbon" where it inverts and flies close to the ground so that a knife attached to the plane can slice a ribbon just off the ground.
No spectators were injured in the crash, which cut short the Thunder Over Solano air show.
Angie Giles, a spectator, said the plane "flipped over to do a trick and hit the ground and dragged over the ground."
The National Transportation Safety Board will head up an investigation. Lunsford added that the FAA was already on site and will be a member of the team.
The pilot had flown planes since he was 16 years old and had performed stuns in shows for 25 years. Andreini's website advertising his air show says "your audience will be thrilled at the sight of this huge biplane performing double outside loops, square loops, torque rolls, double snap rolls, and ... a heart-stopping, end-over-end tumble manoeuvre."