A foreigner commissioned the theft of the Auschwitz sign “Arbeit macht frei” (“Work sets you free”), and the police were seeking help from Interpol and others, Artur Wrona, the chief prosecutor in Krakow, said Tuesday. He said the investigation had exposed “glaring negligence” in security at Auschwitz. He said the thieves drove to the former Nazi death camp on Thursday evening, when it was closed, but found they needed tools to remove the sign. They went to a shop, bought tools and returned after midnight, then unbolted one side of the sign and ripped the other off a gate post, officials said. The sign was cut into three pieces so it could fit in the car.