Kempka left the bunker complex on the following night of 1 May along with SS-Hauptscharführer Heinrich Doose, a driver who was part of his staff.[14] His group went down through the underground railway tunnels and made it to Friedrichstrasse station.[15] At around 2:00 am, another group approached, which included Martin Bormann and Ludwig Stumpfegger.[16] The group followed a Tiger tank which spearheaded the first attempt to storm across the Weidendammer Bridge, but it was destroyed.[17] Bormann and Stumpfegger were "tossed into the air" when the tank was hit.[18] Kempka was knocked down and knocked out.