Two crew members were killed when a medical helicopter crashed in “rugged terrain” east of Phoenix, Arizona, late Tuesday, NBC News reported.
A third crew member survived the crash. No patients were on board.
The chopper went down in “unknown circumstances” just after 8 p.m. local time (11 p.m. ET), a Federal Aviation Administration spokesman said.
It was returning to Globe, Arizona, when it crashed in the Superstition Mountains, according to NBC station KPNX.
The cause of the crash is under investigation.