John Peter Mockus was born in 1920 in Beloit, Wisconsin. He served in the 368th Bomber Squadron, 306th Bomber Group, Heavy, as a Second Lieutenant and Co-Pilot of the B-17 #43-37633 during World War II. He was Killed in Action on December 15, 1944 when his plane, on return from Kassel, Germany, was involved in a mid-air collision with #43-38019 due to bad weather and extremely poor visibility over Greenham Common, UK. It is apparent that neither pilot saw the the other aircraft. 2LT Mockus is now buried in the Cambridge American Cemetery, Cambridge, United Kingdom.