Charlie Keating IV, the Navy SEAL shot dead by ISIS in Iraq on Tuesday, set aside a promising future in sports to join the terror fight overseas, according to friends.

Keating, 31, died in combat in the town of Tel Askuf, likely from AK-47 fire, officials said. He was the third American serviceman to die in combat in Iraq since the U.S.-led coalition launched its anti-ISIS campaign in the summer of 2014.

The Navy SEAL was a former Phoenix high school star distance runner who went on to run cross country and track at Indiana University before attending the Naval Academy and becoming a SEAL based out of San Diego.

His cousin was the former swimming champion Gary Hall Jr., who won a total of ten medals across three Olympics. His father was a three-time All-America swimmer from 1974-77 and finished fifth in the breaststroke at the 1976 Olympics.