Private Nero-Mahar was a member of the Anti-Tank Company, 5th Marines, 1st Marine Division. On 12 June 1953, he and several comrades were returning to their camp from a supply run, when the vehicle in which he was riding accidentally left the road near Whang-bang-ni, South Korea, and rolled down a fifty-foot embankment. He died from the injuries he received.

Nero-Mahar was awarded the Combat Action Ribbon, the Korean Service Medal, the United Nations Service Medal, the National Defense Service Medal, the Korean Presidential Unit Citation and the Republic of Korea War Service Medal.