Repeated pinpoint artillery attacks on Allied assault troops caused their leaders to conclude the abbey was being used by the Germans as an observation post, at the least. Fears escalated along with casualties and in spite of a lack of clear evidence, it was marked for destruction. On 15 February American bombers dropped 1,400 tons of high explosives, creating widespread damage.[40] The raid failed to achieve its objective, as the Fallschirmjäger occupied the rubble and established excellent defensive positions amid the ruins.