ANCHORAGE, Alaska (AP) — A U.S. Air Force pilot was reported to be safe after an F-35 fighter jet crashed Tuesday at a base in Alaska. The accident occurred on the runway at Eielson Air Force Base, but it was not immediately known if the accident occurred while the advanced fighter craft was landing or taking off, Eielson spokesperson Staff Sgt. Kimberly Touchet told The Associated Press.

“It’s still under investigation, so they’re trying to confirm all the details,” she said. Officials planned a news conference later Tuesday.A release from the Air Force said an “incident” occurred about 12:49 p.m. Tuesday, causing significant damage to the aircraft.

“The pilot is safe and has been transported to Bassett Army Hospital for further evaluation,” the statement said.

Eielson Air Force Base is about 25 miles (40 kilometers) south of Fairbanks.

“Our people are our most important resource, and we are committed in ensuring their safety and security,” Col. Paul Townsend, commander of the 354th Fighter Wing, said in the statement. “I can assure you the United States Air Force will conduct a thorough investigation in hopes to minimize the chances of such occurrences from happening again.”

Eielson was selected in 2016 to host F-35s, spawning an expansion that cost more than a half-billion dollars that was to include 36 new buildings and 54 housing units for a full complement of 54 aircraft. The expansion included about 3,500 new active duty airmen and their dependents.

With the capability to fly more than 12 hours at a time, the F-35 can reach almost anywhere in the Northern Hemisphere in one mission.

Nearly 400 miles (644 kilometers) south, Joint Base Elmendorf-Richardson in Anchorage is home to two squadrons of F-22 fighter jets.