brent: the iron gate stolen from the former concentration cap at the cow in 2014 -- at thdacau in 2014. it has been returned and will return to a museum inside the former camp. reporter: the haunting words read "work sets you free." this was the gate at the notorious nazi concentration camp. the rest covered gate has been returned. it was the symbol of suffering endured by prisoners here. they had to pastor the skate every morning and come back every evening. -- to pass through this gate every morning and come back every evening. forced labor, torture, malnutrition, unspeakable suffering. 40,000 people were murdered at this camp alone and 200,000 people from across europe were help heed here. by the end of the war, 6 million jews have lost their lives. this is a memorial site. finding the front gate has been a form of catharsis. it is the culmination of a healing process after an attack on this memorial. the door was stolen because this concentration camp has a worldwide symbolic meaning. this is a healing process. it was found in norway. a replica had been installed in the camp. it wi