 At the first opportunity the American Air Force launched the biggest bombing raid in history on December 24, 1944 to support the besieged ground forces .Over 2,000 bombers from the 8th Air Force and 1,000 bombers from the 15th based in Italy attacked Germany.The target of the 491st for that day was the bridges at Wittlich, Germany in which Mercado flew as a squadron lead bombardier on his 31st mission.