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. His group went down through the underground railway tunnels and made it to Friedrichstrasse station. At around 2:00 am, another group approached, which included Martin Bormann and Ludwig Stumpfegger. The group followed a Tiger tank which spearheaded the first attempt to storm across the Weidendammer Bridge, but it was destroyed. Bormann and Stumpfegger were "tossed into the air" when the tank was hit. Kempka was knocked down and knocked out. After he came to, Kempka came across the badly wounded SS-"Obersturmbannführer" Georg Betz† (Hitler's personal co-pilot and Hans Baur's substitute) and left him in the care of Kaethe Hausermann, a dental surgeon who had been on Hitler's staff working with Dr. Hugo Blaschke. Kempka went on to state that he learned that Betz died from his injuries a short time later.