Second Lieutenant Mairich was a member of the 38th Infantry Regiment, 2nd Infantry Division. He was taken Prisoner of War while fighting the enemy in South Korea on 18 May 1951 and died while a prisoner on 22 October 1951.

Mairich was awarded the Combat Infantryman's Badge, the Prisoner of War Medal, 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.