Dennis F. Lang was born in 1922, in Washington. He was the son of Fred Lang. He enlisted in the service on March 2, 1943. He served in the 525th Bomb Squadron, 379th Bomber Group, as a Second Lieutenant and Co-Pilot of B-17 43-38178 nicknamed 'Seattle Sue' during World War II.

On April 25, 1945, during a bombing mission over Pilsen, Czechoslovakia, two B-17 Flying Fortresses from the 379th Bomb Group—Seattle Sue (serial number 43-38178) and The Thumper (serial number 43-38272)—were tragically involved in a mid-air collision. Seattle Sue reportedly sustained damage to its left engine area or waist section, leading to losing control. While maneuvering, it struck The Thumper, causing catastrophic damage—particularly to The Thumper's tail, which was nearly torn off. Several crew members were killed in the collision, while others survived by parachuting to safety—some were captured and became prisoners of war, while the rest eventually returned to duty.

2Lt Lang 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/, www.americanairmuseum.com