A U.S. Air Force B-1B bomber crashed this morning in near the small town of Broadus in southeastern Montana this morning.

The crash took place sometime before 9 o’clock this morning during what Air Force officials called a routine training mission. Emergency services from around the region were called in to assist with the situation, including volunteer firefighters from nearby Ekalaka and the Carter County Sheriff’s Department.

The bomber that crashed was attached to the 28th Bomb Wing out of Ellsworth Air Force Base. It was one of 28 B-1s in service at the base. The B-1B Lancer is an air-to-ground bomber developed in the 1970s as a replacement for the famed B-52 Stratofortress. It was originally designed to penetrate Soviet airspace quickly, deliver its payload, and evade Soviet air defenses. It entered service in 1986 during the Reagan administration. One hundred of the aircraft were originally delivered to the Air Force. Roughly a third of those remain in service.

The B-1 is crewed by four people: two pilots and two weapons systems officers. Witnesses to the crash said they say parachutes deploying shortly before an explosion as the aircraft was going down. The names of the crew members have not been released, but Colonel Kevin Kennedy, commander of the 28th Bomb Wing, told MTN News that all four had escaped with only minor injuries.

Witnesses said that a plume of smoke from the crash was visible for several hours afterward. The cause of the crash is as yet undetermined. In his statement Colonel Kennedy said that the Air Force’s efforts at present were focused on taking care of the crew and their families and working with local authorities to secure the crash scene.

This is at least the third aircraft the Air Force has lost this summer. Last month we brought you a story about a QF-4 target drone that crashed near a Florida highway. That crash was the second at the same base in less than a month.