Mathis transferred into his brother's unit and began aviation cadet training at Goodfellow Field in San Angelo.

When the crew completed its tour of duty, Mark Mathis stayed in combat and was killed in action over the North Sea in May 1943.

The sports and fitness center at Goodfellow Air Force Base in San Angelo, Texas was named in his honor in 1966.

His right arm was shattered above the elbow, a large wound was torn in his side and abdomen, and he was knocked from his bomb sight to the rear of the bombardier's compartment.

Realizing that the success of the mission depended upon him, 1st Lt. Mathis, by sheer determination and willpower, though mortally wounded, dragged himself back to his sights, released his bombs, then died at his post of duty.

As the result of this action the airplanes of his bombardment squadron placed their bombs directly upon the assigned target for a perfect attack against the enemy.