Reuters reported that a U.S. Air Force B-52 Stratofortress bomber crashed on Monday shortly after taking off from Edwards Air Force Base in California.

According to the report, the aircraft was conducting a test mission related to a radar modernization program. All eight people on board, including military personnel, government employees, and contractors, were killed. U.S. officials said the crash was “unsurvivable,” and the cause of the incident remains under investigation.

The accident is reported to be the first fatal B-52 crash since 2016.