The U.S. Air Force has suspended flights at Hill Air Force Base, Utah, after the landing gear on an F-35A Lightning II collapsed during a landing June 9.

The incident happened at 10:45 a.m. local time, following a routine training flight. The aircraft is assigned to the 388th Fighter Wing at Hill.

A base spokesperson said the pilot was able to get out of the aircraft and is undergoing medical evaluation.

“In response to the incident, the runway is currently closed and aircraft from Hill AFB in flight at the time of the incident have been diverted to other airports,” said Thomas Mullican, Hill AFBs director of public affairs. “Additional training flights have been paused until the runway reopens.”

The incident is under investigation.

This is the second mishap involving Air Force F-35s in a month. An F-35A crashed at Eglin Air Force Base, Fla., May 19. The Lightning II crashed following a routine nighttime training mission. The pilot ejected successfully.