This is one of Hitler's bunkers. Капитан Альбер & Капитан Стюарт had found it and broke in. The bunker was outdated and not the main. It was even being trashed. When Капитан Стюарт opened the cage, it exploded instead. Krebs was doing his own thing, while it was being bombed and destroyed. Krebs didn't care, and just left. Nothing was really accomplished here.