The body of U.S. Air Force pilot Lucas Gruenther was found in the Adriatic Sea on Thursday afternoon after his F-16 fighter jet went missing Monday during a nighttime training mission, Fox News reported.

"It is with great sadness that we announce that the body of Capt. Lucas Gruenther was found in the Adriatic Sea this afternoon," the military told Fox in a statement. "A compassionate husband, a loving son, and a devoted brother; Luc leaves behind a family loves him dearly and a legacy of achievement. We will never fully recover from our loss, but take heart in the knowledge that during his all-too-short time in this world, he made a significant difference in the lives of all whom he met."

On Monday, the military lost contact with Gruenther during his training flight. Although debris from his aircraft were found on Tuesday, Gruenther's family held on to hope that he was still alive, Fox reported.

Brig. Gen. Scott J. Zobrist, commander of the 31st Fighter Wing, told The Union Democrat on Tuesday that "all available resources" were being devoted to finding Gruenther.

The pilot was based at the 31st Fighter Wing, located at Aviano Air Base in Italy, Fox News reported.

His mother, Romel Mathias, flew from Twain Harte, Calif. to Italy on Tuesday with his mother-in-law, Kerry Williams. His wife, Cassy Williams, pregnant with the couple's first child, is in Italy, The Union Democrat reported.

Randy Williams,Gruenther's father-in-law, and other relatives told The Union Democrat that Mathias requested that they not speak to the media.

Gruenther attended Summerville High School in Calif., where he was one of few alumni to enroll in the military, the school's former principal, Dave Urquhart, told The Union Democrat.

"It was very impressive, and we were all very proud of him," he told the paper.