WASHINGTON

Ash Carter, the man who served as former President Barack Obama's final defense secretary, has died at 68, his family announced on Tuesday.

Carter died Monday evening in Boston, Massachusetts following a "sudden cardiac event," his family said in a statement.

Carter served in multiple roles at the Pentagon under Democratic administrations before taking the helm in 2015, serving as Obama's secretary of defense until 2017.

A physicist by training, Carter was the fourth Pentagon chief to hold office during Obama’s two-term presidency.

Carter previously served as the Pentagon’s number two from 2011 to 2013, and was the head of acquisitions for over two years from April 2009 to October 2011.

He earned bachelor’s degrees in physics and medieval history from Yale University, and a doctorate in theoretical physics from Oxford University.