A U-2 spy plane crashed in northern California on Tuesday, killing one pilot and injuring another, the U.S. Air Force said. The plane was on a training mission and took off from Beale Air Force Base, California.

“The aircraft was assigned to 1st Reconnaissance Squadron at Beale Air Force Base, and was on a training mission. Two pilots were onboard and ejected the aircraft.  One pilot is confirmed deceased, while the other sustained injuries,” Beale Air Force Base said in a press release.

According to Col. Larry Broadwell, the base commander, the flight and its path were routine prior to the crash.

“These incidents, while extremely tragic and hard for us to overcome, they're incidents that we do overcome,” Broadwell said. “I am confident that the U-2 squadrons here and the U-2 squadrons around the world are going to come off the mat stronger than they were before.”

Gen. Dave Goldfein, the Air Force chief of staff, offered his condolences on Twitter.

A surveillance and reconnaissance plane, the U-2 “Dragon Lady” can fly above 70,000 feet — about twice as high as a regular commercial airliner flies. Defense contractor Lockheed Martin manufactures the single-engine aircraft.

Beale Air Force Base houses the Air Force’s fleet of single-seat U-2s, as well as double-seat versions that are used for training pilots to operate the specialized aircraft. The U-2 spy planes will reportedly cease operations in 2019 because of the military’s preference for unmanned aircraft for collecting intelligence.