Military aid for the armed insurgent forces came from the American strategic Air Force on September 13, 1944. From September 10, 1944, they registered an increased movement of German transports at the Vrútky railway station. This increase in activity was due to the transferrence of soldiers and military material from the German 1008th and the 1009th Battalions for the support of the 178th Division Tatra. American observation aircraft also registered the movements of the German transports. On September 13, 1944, the Vrútky railway station was attacked by the 2.BG of the 2.BW of the 15.US AF. The unit also planned to bomb the oil refinery in Blechhammer (today, Blachowia Slaska) on the same day. At 11:52, seven B-17Gs left the 168 Fortress aircraft and dropped 56 bombs weighing 250-kilograms (14.6 tonnes) on the Vrútky station. Railway transport was disrupted. Station buildings and fifty railway cars containing military material were destroyed.