Lawrence Manley Colburn, 67, a helicopter gunner in the Vietnam War who helped end the slaughter of hundreds of unarmed Vietnamese villagers by U.S. troops at My Lai, has died.

Lisa Colburn, speaking with the Associated Press on Thursday evening, said her husband of 31 years was diagnosed with cancer in late September and died Tuesday.

Mr. Colburn was the last surviving member of a U.S. Army crew that ended the My Lai massacre of March 16, 1968. According to accounts, pilot Hugh Thompson landed the helicopter between unarmed villagers and American troops and ordered Mr. Colburn and crew chief Glenn Andreotta to cover him.

Thompson then persuaded members of Charlie Company to stop shooting. The company's soldiers had begun shooting that day even though they hadn't come under attack, authorities later said. They added that it quickly escalated into an orgy of killing that claimed as many as 504 civilians, most of them women, children, and the elderly.

Trent Angers, the biographer for Thompson, who wrote The Forgotten Hero of My Lai: The Hugh Thompson Story, said Mr. Colburn played an indispensable role in stopping the massacre at My Lai.

Mr. Colburn and Thompson were nominated for the Nobel Peace Prize in 2001 and received the Soldier's Medal, the highest U.S. military award for bravery not involving conflict with the enemy. Thompson died in 2006. Andreotta was killed in the war three weeks after My Lai. - AP