All eight people aboard a U.S. Air Force B-52 Stratofortress died when the bomber crashed shortly after takeoff from Edwards Air Force Base in California during a routine test mission, officials said.

According to Air Force officials, the aircraft went down around 11:20 a.m. local time on the airfield at the base, located in the Mojave Desert about 95 miles north of Los Angeles. Aerial footage of the crash site showed a huge plume of black smoke rising into the air from a large area of blackened ground. Though emergency services were immediately activated, none of the crew members could survive the dangerous crash.

“Today, Edwards Air Force Base experienced a horrible tragedy, and we lost eight great Americans,” said Colonel Hayes in a media address.

The flight had been in support of the US Air Force’s “radar modernisation program”, and had carried a “mixed crew” of military personnel, civilian government employees, and government contractors. So far the reason of the crash is not determined.

Officials took to their social media handles expressing condolences. We mourn this loss and honor the service of our Airmen, civilians, and contractors who work every day to advance our mission,” Air force secretary Meink said in a post on X.

US House of Representatives Speaker Mike Johnson also paid tribute to the deceased crew. “The roar of a B-52 is a familiar sound to all of us in Bossier City, Shreveport, and the surrounding region, and reminds us daily of the courage and sacrifice of those in uniform,” Johnson said on X.

The crew’s next of kin are being notified and they will be named 24 hours after that, Hayes said in an afternoon briefing.

The crash was “totally contained” within the Edwards Air Force Base on the runway, Hayes said, and the base has temporarily grounded operations.