As of January 1942 Stutthof became an official concentration camp. Brutal SS guards led the forced labor. Stutthof prisoners worked in German owned businesses, local brickyards, industrial enterprises, agriculture, and workshops within the camp's fences. Prisoners deemed too ill to work were quickly led into the gas chambers. Following the gas chamber the corpses were cremated. Doctors took advantage of sick prisoners by killing the prisoners by means of lethal injection. They then used the corpses as cadavers. The camp was surrounded by electric barbed-wire fences. Brutal winters led to typhus outbreaks in 1942 and 1944. More than 60,000 prisoners died at Stutthof. Beginning in April 1945 the remaing 50,000 Stutthof prisoners were evacuated to neutral countries. Nearly 25,000 prisoners died in the process. May 9th, 1945 the camp was liberated. Nearly 100 prisoners were found inside the camp after hiding during the final evacuation ("Stutthof." United States Holocaust Memorial Museum).