SIOUX FALLS, S.D. (AP) — An Air Force commander says he's thankful that four crew members were able to safely eject before a B-1B bomber crashed in southeastern Montana.

The airplane crashed Monday in a remote area near Broadus, Mont. It was based at South Dakota's Ellsworth Air Force Base, one of only two bases in the U.S. that have B-1B crews.

Col. Kevin Kennedy says two 28th Bomb Wing pilots and two weapons system officers were taken by ambulance and air to South Dakota hospitals in Rapid City and Spearfish. He says their injuries are not life threatening.

No details were released about what may have caused the crash, which occurred about 170 miles southeast of Billings, Mont.

Kennedy says the Air Force will conduct a thorough investigation.