On April 10, 1945 the Nazi’s intend to liquidate the twenty some thousand remaining captives. An allied air raid caused everyone to take cover. The next day local resistance units drove off the Nazis, followed shortly by US armored units.
Below is excerpt from a summary of Night.
Sorry, do not have access to the actual book.
with about 20,000 people remaining in the camp, the Nazis decide to evacuate—and kill—everyone left in the camp. As the evacuation begins, however, an air-raid siren sounds, sending everybody indoors. When it seems that all has returned to normal and that the evacuation will proceed as planned, the resistance movement strikes, driving the SS from the camp. Hours later, on April 11, the American army arrives at Buchenwald. Now free, the prisoners think only of feeding themselves. Eliezer is struck with food poisoning and spends weeks in the hospital, deathly ill. When he finally raises himself and looks in the mirror—he has not seen himself in a mirror since leaving Sighet—he is shocked: “From the depths of the mirror,” Wiesel writes, “a corpse gazed back at me.”