The pilot of an F-16 Fighting Falcon was killed after crashing just 20 miles southwest of Safford, Ariz., on Tuesday.

"All I can say is we do have a crash, and it appears to be an Air Force jet," Graham County Sheriff PJ Allred said, according to the Eastern Arizona Courier. "We're waiting on the inspectors from Davis-Monthan (Air Force Base, in Tucson) to come out."

Sen. John McCain, R-Ariz., tweeted he was closely monitoring the crash and the search-and-rescue efforts.

Closely monitoring F-16 crash in #Arizona as search and rescue efforts continue https://t.co/u99MxzXpZH — John McCain (@SenJohnMcCain) September 6, 2017

No other injuries have been confirmed yet and the cause of the crash has not been released yet.