A U.S. Air Force F-15C Eagle fighter jet crashed under unknown circumstances into the North Sea, according to the 48th Fighter Wing Public Affairs.

“A U.S. Air Force F-15C Eagle crashed at approximately 0940 today in the North Sea,” said in a statement on an official Twitter account.

The aircraft was from the 48th Fighter Wing, the aircraft was on a routine training mission with one pilot on board.

At the time of the accident, the aircraft was on a routine training mission with one pilot on board. The cause of the crash as well as the status of the pilot are unknown at this time, and U.K. Search and Rescue have been called to support.

According to the Sun. the east Yorkshire and Bridlington coastguard has confirmed a major operation is underway.

Just this morning, RAF Lakenheath had shared photographs of three fighter jets.