John Joseph O'Brien was born in 1917 in Bronx County, New York. He served in the 812th Bomb Squadron, 482nd Bomb Group, Pursuit, as a Flight Officer and 2nd Navigator of B-17G #42-3486 nicknamed ''Invictus'' during World War II.

On January 11, 1944, B-17F “Invictus” departed Thurleigh, England, on a Pathfinder mission leading a bombing formation to Halberstadt, Germany. After releasing its bombs and heading back toward England, the aircraft came under repeated attacks from German fighter aircraft and possibly anti-aircraft rockets, which severely damaged the tail section and killed or incapacitated the tail gunner. Despite the damage, the bomber continued west toward the Dutch coast. Near the Netherlands, it was attacked again by a large formation of German fighters, including Fw 190s and Me 109s. During this final attack, the aircraft was struck heavily, and two engines caught fire. The aircraft lost control, stalled, and entered a steep dive. Four crew members managed to bail out before the aircraft crashed into the IJsselmeer near Harderwijk, Netherlands, at approximately 1:30 PM. One survivor landed on land but was injured and captured, two others parachuted into the lake and were rescued and taken prisoner, while one drowned. The remaining crew members were killed in the crash.

FO O'Brien was killed in action, and his remains were later recovered from the water or found washed ashore in the months after the crash. He is now buried in the Ardennes American Cemetery and Memorial, Neuville-en-Condroz, Arrondissement de Liège, Liège, Belgium.

Source of information: www.findagrave.com, https://aviation-safety.net, weremember.abmc.gov