Evacuation, not Liberation
As the Allies approached the Nazi camps in the days and weeks before liberation, the SS ordered "evacuations" of many concentration camps, mostly in part to keep many of the prisoners in the camps from falling into Allied hands, where they would then be able to freely tell there story. The SS also thought that they could keep prisoners and use them to continue armament production and they also believed that they could be kept as hostages and used as bargaining chips against the Allies and would allow the Nazi regime to remain alive. Soon after evacuations, the SS tried to destroy as much and as many of the camps as possible before they were taken over by The Allies.
Majdanek Nazi camp near Lublin, Poland, 1944
The German's demolished as much of the evidence as they could before the Allies approached. The staff set the crematorium on fire to extinguish any evidence of the atrocities that took place there.
Auschwitz, Dachau, Buchenwald, Flossenburg and Dora-Mittelbau
Nazis forced prisoners on evacuation marches before the Allies could arrive at the camp. These marches became known as the "death marches" because of the horrible conditions prisoners had to endure. Some of the marches, such as one from Dachau, included thousands of prisoners. During the marches, German's shot anyone who couldn't continue and many other died from starvation, exhaustion, etc. The forced marches from Flossenburg advanced on foot and by train en route to Dachau.
The Stutthof camp system evacuation, northern Poland
Evacuations began in January of 1945. Out of the 50,000 prisoners in camp system, 5,000 from subcamps were marched to the Baltic Sea, forced into the water and shot. Some of the camp's prisoners were marched toward Germany through brutal winter conditions. During the month before liberation, remaining prisoners were sent to nearby camps, nearby neutral countries, more were brought to the Baltic Coast to be shot and others were transported by small boat to Germany, many drowning along the way. During the evacuations of this camp system, about half of the prisoners died.
The Neuengamme camp system evacuation, Germany
During the first couple days of May, 1945 the Germans evacuated some 9,500 prisoners from the camp system onto 3 different ships anchored off the Baltic Coast. The British attached two of the German ships during a raid and about 7,000 of the prisoners were killed. From the three ships, only about 600 prisoners survived.