The longest-held American civilian prisoner during the Vietnam War has died.

Ernie Brace was held in multiple North Vietnamese prisons. He was eventually housed in a cell next to Sen. John McCain during his captivity.

“I am deeply saddened by the death of my friend and fellow POW Ernie Brace,” McCain said in a statement Monday. “As the longest-held American civilian prisoner detained for nearly eight years in Vietnam, Ernie endured more cruelty and severe torture than any other captive during the Vietnam War."

Brace landed his small plane on a dirt strip in northern Laos in May 1965. The plane was disabled by ground fire. Enemy soldiers captured Brace and a Thai sergeant. He was eventually transferred to a prison in North Vietnam. He was held in a bamboo cage and beaten. He tried to escape twice and, after the second attempt, was buried up to his chin for seven days.

He was then transferred to, the infamous Hanoi Hilton prisoner-of-war prison. McCain, a young naval aviator, was in the cell next to him. The two captives communicated by tapping on the walls of their cells.

Brace was finally released with other prisoners of war in 1973, having spent nearly eight years in captivity. He and McCain finally met face-to-face that year at a White House event – nearly four years after they began communicating with each other.

“Serving with Ernie was one of the greatest privileges of my life, and I am forever grateful for his friendship,” McCain said.

Brace was 83.