William J. O'Brien was born on May 18, 1925, in Jacksonville, Duval County, Florida. He enlisted in the Army Air Corps on December 13, 1943. He served in the 352nd Bomber Squadron, 301st Bomber Group, Heavy, as a Sergeant and Waist Gunner of B-17G #42-97728 nicknamed ''None'' during World War II.

On November 15, 1944, the B-17G “None” took off for a bombing mission targeting Linz, Austria. During its return flight to Foggia, Italy, the aircraft encountered severe weather conditions and engine trouble while crossing the Alps. Around 10:42 local time, the crew issued a Mayday distress call, highlighting the worsening situation. As the bomber struggled to stay aloft, two crew members were able to bail out, while the aircraft ultimately crashed near Kleinsölk, southeast of Salzburg. Of the ten crew members, eight lost their lives, and the two survivors became prisoners of war. The wreckage remained undiscovered for decades until it was finally located in 2004.

Sgt O'Brien was Killed in Action and is now buried in the Lorraine American Cemetery and Memorial, Saint-Avold, Departement de la Moselle, Lorraine, France.

Source of information: B17flyingfortress.de, B-17 Missing Aircraft Project – MACR Database