 On 23 December 1944, while supporting German forces in the Battle of the Bulge Bartels was shot down by United States Army Air Force (USAAF) P-47 Thunderbolts belonging to the US 56th Fighter Group after achieving his 99th aerial victory and he was posted missing in action.On 26 January 1968, 23 years later, Bartel's fighter and remains were found near Bad Godesberg, Germany.Born in Linz, Austria, Bartels was working as a butcher when Hitler came to power.