A U.S. Naval Academy midshipman from Flower Mound died Saturday while he was taking a fitness test in Annapolis, Md., according to a post on the Naval Academy’s Facebook page.

Duke Carrillo, 21, collapsed during a 1.5-mile run in the semiannual physical readiness test, according to the Facebook post. He was rushed to the Anne Arundel Medical Center, where he was pronounced dead. The cause of his death is being investigated, the Naval Academy said.

Carrillo was a member of the class of 2022 majoring in quantitative economics. He was a member of the 24th Company, participated in extracurricular activities and aspired to be a naval aviator, the post said.

“My wife, Joanne, and I join the Brigade, staff and faculty in mourning the sudden and tragic loss of Midshipman Duke Carrillo,” said Vice Adm. Sean Buck, superintendent of the Naval Academy. “Our most heartfelt sympathies and condolences go out to the entire Carrillo family, and our extended Naval Academy family, during this extremely difficult time.”

In a 2012 report from The Dallas Morning News, Carillo was featured in a roundup of Eagle Scouts. Carrillo, 13 at the time, had designed, built and installed wooden tables at an outdoor learning area for Lewisville ISD.

Carrillo attended the Naval Academy with his twin brother, Dylan, and his younger brother, Jake. He is survived by his parents, Gerald and Jennifer Carrillo, and his brothers.