Former U.S. defense secretary Ash Carter dies at 68

Ash Carter, who led the U.S. Department of Defense through the final years of President Obama’s second term, died Monday. He was 68.

Carter died after suffering a heart attack, Douglas Elmendorf, dean of Harvard University’s Kennedy School, said in a statement Tuesday. Carter was the director of the school’s Belfer Center for Science and International Affairs.

He was deputy defense secretary from 2011 to 2013, and led the department from 2015 until the end of Obama’s second term in early 2017.

In 2015, he opened all U.S. military positions up to women, and the next year removed the military’s ban on transgender officers, though Donald Trump reinstated it in 2017.