BOISE, Idaho (AP) — Four crew members ejected safely after two Navy jets collided Sunday at an air show in Idaho, a show organizer said.

Emergency crews responded after the two planes collided during the show at the Mountain Home Air Force Base in western Idaho.

All four of the crew members from the planes ejected safely, said Kim Sykes, marketing director with Silver Wings of Idaho, which helped to plan the air show. Sykes said the crash occurred off base and she did not see the crash but saw the smoke afterward.

The base said in a social media post that it was locked down following the incident during the Gunfighter Skies Air Show. Responders were on the scene and an investigation was underway.

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Multiple witnesses reported two planes collided and crashed, and videos posted online showed four parachutes opening in the sky as the aircraft plummet to the ground near the base about 50 miles (80 kilometers) south of Boise.

No other information was immediately available, said a person who answered the phone at the 366th Fighter Wing public affairs office.

Organizers said the popular air show that includes flying demonstrations and parachute jumps is a celebration of aviation history and a look at modern military capabilities. The U.S. Air Force Thunderbirds headlined the show both days.

The National Weather Service reported good visibility and winds gusting up to 29 mph (47 kph) around the time of the crash.