The Air Force has identified an F-22 Raptor fighter pilot who died Sept. 23 on Guam as Capt. Jeffrey “Bull” Braden, who was based in Hawaii and on Guam at the time on temporary assignment.

Braden, 28, of San Antonio, was found unresponsive at San Luis Beach on Naval Base Guam and later pronounced dead at Naval Hospital Guam, according to the 15th Wing at Joint Base Pearl Harbor-Hickam.

The Air Force said the incident is under investigation.

The active-duty pilot was with the 19th Fighter Squadron in Hawaii but was temporarily assigned to Andersen Air Force Base as part of Exercise Valiant Shield.

“Our thoughts and prayers are with, and will continue to be with, Capt. Braden’s loved ones during this incredibly difficult time,” Col. Kevin Gordon, 15th Wing commander, said in a news release. “Capt. Braden was an outstanding officer, fighter pilot, and leader. He will forever be our Air Force brother, and we will continue to offer his friends and family our support.”

A GoFundMe request for donations said Braden was found unresponsive in the water at San Luis Beach.

“The Hawaiian Raptor community has lost one of our best — a promising young fighter pilot, a husband, father, brother, son, nonstop comedian, and loyal friend,” the page states, adding he is survived by wife Layne, a young daughter and an unborn child.

Donations are being collected at gofundme.com/2quyr24 for travel and unforeseen expenses.