Newt Heisley, the designer of the POW/MIA flag adopted by Congress in 1990 as a symbol of the nation's concern for those missing during military actions in Southeast Asia, died. He was 88.

Donna Allison, Heisley's fiancee, told The Associated Press Heisley died suddenly Thursday at his home after years of failing health. His death was first reported by The Gazette.

Heisley's image sketched in pencil in 1971 during the Vietnam War shows the silhouette of a gaunt man, a strand of barbed wire and a watchtower in the background with the words POW/MIA "You are not forgotten."

Congress in 1998 mandated the flag be displayed at the White House, U.S. Capitol, military installations and other federal buildings on national observances that include Memorial Day and Fourth of July.