While conducting a "reconnaissance in force" operation in the Dodge City area, in the vicinity of Nong Son hamlet, Dien Ban District the Marines made heavy contact with a large enemy force.

Corporal Cavanaugh acting as Platoon Sergeant quickly deployed his men, encouraged them to battle the enemy and assisted in recovering and assisting the wounded before being mortally wounded himself.

For his courageous actions on that day he was awarded the Navy Cross Medal.