Due to increasing mortality from the harsh conditions, the SS ordered the construction of an on-site crematorium, which was completed in May 1940. Executions by shooting began at Flossenbürg on 6 February 1941; the first victims were Polish political prisoners. Victims were separated after evening roll call and read their sentence. After a night in the camp jail, they were shot at the firing range adjacent to the crematorium. After a mass execution of 80 Polish prisoners on 8 September, the execution method was changed to lethal injection due to complaints from local residents of blood and body parts washing up in nearby streams. The primary victims were Polish political prisoners and Soviet prisoners of war.