Operation Valkyrie was a plan initiated by German Army officers and civilians to assassinate Adolf Hitler during World War II. The members of the operation were led by Colonel Claus von Stauffenberg, with Major General Henning von Tresckow, Lieutenant Colonel Mertz von Quirnheim, and Major Albrecht Ritter Mertz von Quirnheim as his chief aides. On July 20th 1944, Von Stauffenberg placed a bomb in Hitler's headquarters in East Prussia but it failed to kill him. As a result of their actions, all of the conspirators were arrested that same day and interrogated for weeks until they were sentenced to death on August 10th 1944. Most of them suffered gruesome deaths at Plötzensee Prison near Berlin; however some managed to survive due to being released from prison or taking their own lives before execution.