PENSACOLA, Fla. -

The U.S. Air Force says an airman died during survival training at Pensacola Naval Air Station.
    
The Air Force confirmed Wednesday that Maj. Garrett Knowlan died last week during a four-day, water-survival course.
    
Knowlan was a 2002 graduate of the Air Force Academy and a 2010 graduate of the Air Force Test Pilot School.
    
Military officials did not immediately provide other details about Knowlan's death. They say an investigation is underway.