Private Serna was a member of the 5th Cavalry Regiment, 1st Cavalry Division. He was seriously wounded by the enemy in North Korea on 3 October 1951 and returned to duty on 9 October 1951. He was Killed in Action while fighting the enemy in North Korea on 28 October 1951.

Serna was awarded the Purple Heart with Oak Leaf Cluster, the Combat Infantryman's Badge, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal and the Republic of Korea War Service Medal.