In order to kill as many undesirables as fast as possible, Nazi soldiers created many methods that could eliminate hundreds of people in a matter of minutes. One technique they used were gas chambers. These were large, airtight rooms that were filled with the poisonous gas, Zyklon B, that could kill hundreds in less than 15 minutes. In order to muffle the screams, soldiers would rev the engine of a motorcycle and make it seem as if nothing had happened. When people did not pass the selection because they were unfit to work, this is where they were sent to be executed. Doctors also performed deadly medical experiments on the prisoners such as freezing them and performing surgery on the while they were awake to see how their bodies reacted.
