CBS News correspondent Richard Roth reports at dawn Friday, the sign was missing. It was stolen, according to Polish police, by thieves who entered Auschwitzthrough a gap in a wall overnight and cut through barbed wire to get away.
"It is unbelievable," said a spokesman for the Auschwitz Museum. "Sad, and frustrating."
A replica of the 90-pound sign was quickly bolted into place. But the theft was condemned as sacrilege by survivors of the holocaust.
Noah Flug, a survivor of Auschwitz, said, "when we, that have been their prisoners, shall not be more, Auschwitz is a symbol you can see there what happened."
What did happen beyond the sign - with its cynical slogan promising "freedom through work" -- was the biggest mass murder in history.
More than a million prisoners, mostly Jews, died in the Nazi death camp between 1940 and 1945. Many of them exterminated in gas chambers.
With age and weather wearing on Auschwitz, there'd just been agreement on money to preserve the memorial.
Poland's chief rabbi said whoever stole the sign has vandalized world memory.