After the war there were many arguments that the Allies could have done more to bomb the Nazi death camps. It was argued that it should have been possible to breach the perimeter wires and enable inmates to escape, or to blow up the crematoria, putting a halt to the killings. Although the Allies had a lot of evidence of the Nazi programme to kill Jews, and others, by 1944, there was no strategic plan to save people, either by bombing or other means. It was argued that the best course of action to help the Jews was to seek to bring the war to a close as soon as possible.
There would have been many difficulties in accurately bombing the camps. Although many claims were made for the “precision bombing” at the time all the evidence shows that this was very difficult to achieve, and impossible to achieve consistently.
There is one example of what could have happened had the Allies chosen to to bomb the concentration camps. Semlin (Sajmište in Serbian) Judenlager was established by the Germans in Serbia in 1941 and first used for the killing women and children using gas vans in the spring of 1942. Thereafter it was used to detain political prisoners and anyone else caught up in the Nazi persecution in Serbia, where it was the largest camp.
The USAAF bombed Belgrade on 17th April 1944, Semlin was not part of the area targeted but it was hit. Bombs hit the camp and the perimeter fence, enabling some inmates to attempt to escape. The outcome was not what the inmates would have sought. This is the account of Dr Dragomir Stevanović:
On the second day of Easter, we found ourselves in what felt like the middle of Mount Etna, or a scorching geyser. Above and below us everything shuddered, flared, and burned, while we suffocated in clouds of dust and smoke. I lived through the [German] bombing of April 1941, but it was never like this. The square [in the middle of the camp] was covered with corpses and torn bodies, and the sand was saturated with fresh and coagulated blood: a real carnage! We lost around 190 people.
Besides the dead, there were several hundred wounded, so the surviving pavilions were turned into hospitals. There were no beds, and certainly no bandages or surgical equipment, although we did have several doctors and surgeons among the interns …
[…] During the bombing, the fence was damaged and a number of concrete poles that were holding it in place were dislodged. Several groups of interns tried to escape. However, because of the bareness of the terrain leading towards the River Sava and to Zemun, they were all mowed down by gunfire. Their bodies were brought back to the camp. We never found out how many died.
Read more about Semlin Judenlager