Soviet forces liberated the Sachsenhausen camp itself on April 22, 1945. They found only about 3,000 ill and weak prisoners in the camp. Camp records indicate that the SS deported more than 140,000 prisoners to the Sachsenhausen concentration camp. Though a Soviet investigation commission estimated that over 100,000 prisoners died at Sachsenhausen, new research shows that a more realistic estimate is between 30,000 and 50,000 deaths. The SS also deported to Sachsenhausen tens of thousands of unregistered prisoners. The SS authorities interned an estimated number of 200,000 prisoners in Sachsenhausen during the camp's operation.