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DALLAS (NewsNation) — Transportation investigators are trying to determine why two historic military planes were seemingly in the same place at the same time just before they collided at a Dallas air show, killing six people. 

The crash claimed six lives, Dallas County Judge Clay Jenkins tweeted Sunday, citing the county medical examiner. Dallas Fire-Rescue said there were no reports of injuries on the ground.

Those killed include Dan Ragan, Kevin Michels, Maj. Curtis J. Rowe, Terry Barker, Len Root and Capt. Craig Hutain.

The collision happened Saturday afternoon at the Commemorative Air Force Wings Over Dallas show at the Dallas Executive Airport. The Federal Aviation Administration says a Boeing B-17 Flying Fortress and a Bell P-63 Kingcobra collided and crashed.

Several videos posted on social media showed the Kingcobra fighter plane flying into the bomber.

“One of the things we would probably most likely be trying to determine is why those aircraft were co-altitude in the same air space at the same time,” Michael Graham, a member of the National Transportation Safety Board, said at a news conference.

Witness Victoria Yeager, who was once married to famous test pilot Chuck Yeager, said all she could see from the moment of impact was “just complete fire.”

“Everything was gone in seconds,” she said. “The plane. The people. We all were hoping there was some way they could have walked away or could have jumped out or something but that just wasn’t the case.”

Armin Mizani, the mayor of Keller, Texas, said Barker, a retired pilot who lived in Keller, was in the B-17 bomber that crashed. Mizani said he learned of Barker’s death from his family.

Barker was an Army veteran who flew helicopters during his military service. He later worked for American Airlines for 36 years before retiring in 2020, Mizani said.

Rowe, a member of the Ohio Wing Civil Air Patrol, was a crew chief on the B-17, his brother-in-law Andy Keller told The Associated Press on Sunday. Rowe, of Hilliard, Ohio, did air shows several times a year because he fell in love with WWII aircraft, Keller said.

Graham said five people were in the B-17 and a pilot was the only person in the P-63. The aircraft are owned by Commemorative Air Force, the company that put on the air show. They are flown by highly trained volunteers, often retired pilots, said Hank Coates, president of Commemorative Air Force.

Neither plane had a black box flight recorder installed.

Investigators will examine the wreckage from both aircraft, conduct interviews of crews present at the air show and obtain pilot training and aircraft maintenance records.

A preliminary report from the NTSB is expected in four to six weeks, while a final report will take up to 18 months to complete.

The Federal Aviation Administration is investigating, officials said.