A decorated US Navy Seal died over the weekend after a freefall parachute training exercise in Arizona, authorities said.

Chief special warfare operator Michael T. Ernst was pronounced dead at Banner University Medical Center following military training at Marana on Sunday, the Naval Special Warfare Command said in a statement.

Chief of Special Warfare Operations Michael T. Ernst.US Naval Special Warfare Command

It is not clear what happened during the exercise and the Navy is investigating the cause of the incident.

The Naval Special Warfare Command said: «It would be inappropriate to comment further on the ongoing investigation until it is complete.»

Ernst, from Massachusetts, was assigned to an East Coast-based unit of Naval Special Warfare.

Rear Admiral Keith Davids, commander of Naval Special Warfare Command, remembered Ernst as «an exceptional teammate.»

“He was a dedicated NSW sailor who applied his talents and skills to some of our nation’s toughest challenges, while selflessly mentoring his teammates. Mike and his family will always be a part of the NSW family and we will never forget him,” added Davids.

Ernst enlisted in the Navy in 2009 and attended SEAL training the following year. He spent much of the last decade assigned to an East Coast Special Warfare Unit.

Ernst earned a host of awards and decorations in his time in service, including a Silver Star, the third-highest military combat decoration awarded for gallantry in action, a Defense Meritorious Service Medal, and four Army Achievement Medals. Navy and Marine Corps.