Jan Kubiš acted as a lookout for Reinhard Heydrich's approaching car, while his partner, Jozef Gabčík was to shoot Heydrich from the street. However, Gabčík's STENS jammed. Kubiš then tried to throw a grenade at the car, but Heydrich noticed, and ordered his driver, Johannes Klein to flee. The car moved far enough out of range of the explosion that while the vehicle was badly damaged, with both Heydrich and Klein received minor injuries.
Kubiš and Gabčík died in a gun fight with German troops a short time later.