An F-16 has crashed at Nellis Air Force Base in Nevada, but it is not yet known whether the pilot is safe.

The F-16 crashed at about 10:30 a.m. Wednesday during routine training on the Nevada Test and Training Range, Nellis said in a release.

“The condition of the pilot is unknown at this time,” the release said.

Nellis said that emergency responders are on the scene, and that the accident is under investigation.

This is Nellis’ first crash since two back-to-back crashes at the Nevada Test and Training Range last September, one of which was fatal.

On Sept. 5, Lt. Col. Eric Shultz died when his plane crashed at the range. The Air Force has still not identified what Shultz was flying, but said it was assigned to Air Force Materiel Command. Chief of Staff Gen. Dave Goldfein later told Military.com it was not an F-35.

And one day later, two A-10C Warthogs from the 57th Wing at Nellis crashed during what was called a routine training mission at the Nevada Test and Training Range. Both pilots ejected safely.

This is a breaking news event and will be updated.

Valerie Insinna contributed to this report.