Lesser known was the other massacre at Malmedy itself where 200+ Belgian civilians and about 30 American servicemen were killed by misguided bomb runs from elements of the 9th Army Air Force.
Viking Battalion, which was manned by Americans of Norwegian descent and Norwegian nationals who had fled German occupation and Vidkun Quisling's puppet government. Eventually Malmedy was further reinforced by elements of the 120th Infantry Regiment of the 30th Infantry Division.
The first blue-on-blue bombing run was on 23 December. With cloudy skies, six lost B-26s bombed Malmedy. All the bombs detonated around and through the town center. It turned out to be a navigation error, although there were many rumors that Malmedy was the target because the BBC had broadcast that Malmedy had been captured by the Germans. The town center was devastated: fires, collapsed buildings, blocked roads and streets, and many civilians and soldiers buried alive under the rubble. The 291st engineers were critical in putting out the fires and digging out survivors. And their aid station, run by an Army dentist as they did not have an assigned doctor, treated about 150 wounded civilians and GIs.
1st Army HQ raised hell with the 9th Air Force and got back a pro forma letter indicating they would try to avoid such incidents in the future. Unfortunately they did not. The very next day, on the afternoon of Christmas Eve, 18 B-24 heavy bombers made the same mistake. And in the words of a witness: "They made the previous days B-26 bombardment look like just an appetizer for a B-24 seven course feast".
But it was not over, for dessert the flyboys got lost again on Christmas Day. Four B-26s dropped sixty-four 250-pounders on Malmedy instead of their authorized target of German formations at Sainte Vith.
The 291st was awarded a Presidential Unit Citation for their defense of Malmedy and stopping Kampfgruppe Peiper. Later they went on to build the first bridge across the Rhine while under observed artillery fire, and luftwaffe strafing and bombing. Many of those luftwaffe attacks were by ME-262 jet aircraft. Their bridge site also sustained attacks by eleven V-2 rockets. They ended up the war by bridging the Danube, thankfully while not under fire.
A TV documentary titled 'Those Damned Engineers' was made about the 291st. The title reputedly came from when a bridge at Lienne creek was blown right in front of Peiper's eyes. That bridge had been his last hope. The story, true or not, was that the frustrated Peiper banged his fist on his knee and swore 'Deise verdammten Pioniere'. True or not I do not know, perhaps true or perhaps embellished over the many years since.