Six people were killed when two historic military planes collided and crashed during a Dallas air show on Saturday, officials said.
Dallas County Judge Clay Jenkins tweeted: “According to our Dallas County Medical Examiner, there are a total of six fatalities from yesterday’s Wings Over Dallas air show incident.”
He said authorities were continuing to work to identify the victims.
The Boeing B-17 Flying Fortress and a Bell P-63 Kingcobra collided and crashed around 1.20pm local time, the Federal Aviation Administration (FAA) said in a statement. The collision occurred during the Commemorative Air Force Wings Over Dallas show.
Emergency crews raced to the crash scene at the Dallas Executive Airport, about 16km from the city centre.
News footage from the scene showed crumpled wreckage of the planes in a grassy area inside the airport perimeter.
Dallas Fire-Rescue told The Dallas Morning News that there were no reported injuries among people on the ground.
Anthony Montoya saw the two planes collide.
“I just stood there. I was in complete shock and disbelief,” said Mr Montoya (27) who attended the air show with a friend.
“Everybody around was gasping. Everybody was bursting into tears. Everybody was in shock.”
Officials did not specify how many people were inside each plane but Hank Coates, president of the company that put on the air show, said one of the planes – a B-17 Flying Fortress bomber – typically had a crew of four to five people. The other, a P-63 Kingcobra fighter plane, had a single pilot.
No paying customers were on the aircraft, Mr Coates, of Commemorative Air Force, which also owned the planes, said.
Their aircraft were flown by highly trained volunteers, often retired pilots, he said.
Dallas mayor Eric Johnson said the National Transportation Safety Board (NTSB) had taken control of the crash scene, with local police and fire providing support.
“The videos are heartbreaking,” Mr Johnson said on Twitter.
The planes collided and crashed around 1.20pm local time, the FAA said in a statement.
The B-17, a cornerstone of US air power during the second World War, is an immense four-engine bomber which was used in daylight raids against Germany. The Kingcobra, a US fighter plane, was used mostly by Soviet forces during the war.
Most B-17s were scrapped at the end of the second World War and only a handful remain today, largely featured at museums and air shows, according to Boeing.
Several videos posted on social media showed the fighter plane appearing to fly into the bomber, causing them to quickly crash to the ground and setting off a large ball of fire and smoke.
Air show safety – particularly with older military aircraft – has been a concern for years.
Wings Over Dallas bills itself as “America’s premier second World War Airshow”, according to a website advertising the event.
The FAA was also launching an investigation, officials said. – AP