Even though there was a cooling off period, the Germans were still on the lookout for more tunnels. They were also well aware of tunneling activity in other camps and no doubt still having thoughts of the large escape of prisoners at Oflag 17A Austria a year earlier. Some 6000 POW's mainly French offices were held there and 132 escaped over two nights in September 1943, but almost all were quickly caught.
The men had smuggled in a movie camera...in parts.. hidden in SAUSAGES, rebuilt it in camp, and then made over 30 secret films of life in the camp, about 450 miles south of Stalag Luft lll, but in Austria. There is a movie on the net showing snipets of the films taken and depict daily life and escape activity including them making carvings out of boot heels, making phoney documents, compasses and even digging in the tunnels. This actual footage and can be seen at http://www.gizmodo.com.au/2013/08/the-astonishing-tale-of-nazi-prisoners-a-smuggled-camera-and-survival/ and shows camp and activities no doubt quite like those at Stalag Luft lll.
Back at HARRY, tunnelling had been going on daily since restarting it in early January 1944. By early March it had passed under the gate wire obstacles and the POW's were ready to break ground, with just a few feet at the top of the escape shaft left to go. Those few feet would trade years of captivity to freedom for hundreds. So went the plan!
Final preparations were tightened up, uniforms and civy clothes and maps and compasses were lined up and language last minute tutoring was on going. A moonless night was now being waited on and then it came of March 24th. Last minute dates were then put on the forged documents.
The Senior Allied Officer presided over the selection of men to go. Five hundred wanted to be among those going but all knew that with timings involved. less than 200 could be scuttled through in the dark and before daylight and perhaps as many the next night . The first 200 chosen were men with the best chances of survival. Those with contacts nearby on the outside. Those speaking European languages and especially German and with experience in Europe on the civy street. The next 70 would be those who contributed the most above and below ground. The remaining hundred selected for the first night were draw from a hat.

The date was further picked because it would not be long before the temperature would rise and with that would come the melting snow, the build up of water, and it sinking down into the earth, making the sand above the tunnel much heavier and greatly increasing the possibility for a collapse.
The GO was finally given and around 8.30 at night the men, 200 strong, piled into hut #104 awaiting the word to get into the tunnel. These men had gathered up many of their belonging and in many cases even travelled with a suitcase full of treasures. They also had on several layers of clothing to ward of the frigid temperatures and deal with the fresh blanket of snow that had just come down. (Despite the Great Escape 1963 moving of a breakout in spring weather conditions)
But then things started to go wrong!
It would take several minutes, according to the plans, to get each man out. Move through the tunnel would start at dark and end at daylight. Possible 150 could make it in that time, with others on hand in the hopes things went quicker than planned. But they went slower. Much slower.
To begin. The entrance trap door had frozen over. It took over an hour to break it free. Then the men started to enter. But many of these officers had never been in the tunnel before. Some panicked. Others had claustrophobia, still others would jerk around needlessly while on the route through. Some actually got stuck because they were too bulky due to all the extra clothing worn, or a suitcase bumping into the side walls. Two minor collapsed took place.
In all of this men had to be backed out, and repairs made on the spot and then men sent in again. When the first officers got to the exit end, the final few feet had to be removed. But the hatch was also frozen over and took about 30 minutes to free up. Once this was done, to their horror, they discovered that the tunnel WAS NOT LONG ENOUGH. It was short some 30 feet and was only about 45 feet from a guard tower. AND WORSE THAN ALL THIS... it was in OPEN GROUND because of recent chopping down of trees that once had the forest much closer to the fort.
The first out had to make on the spot emergency plans that would take into account the guard roaming patrols and the powerful search light activity in the area. They came up with a plan to stretch a rope across the open ground and hide in the bushes and tug on it to send a message of the ALL CLEAR when it was safe for another to exit. But they had to send a message back, and from man to man in the tunnel to the opening that rope was needed at the other end. Yet another delay. When it arrived it was put into play and the men started finally emerging, dashing to the woods, waiting for their escape partner to exit and then heading off to freedom.
During all of this an air raid siren went off and the camp quickly shut down all the power. And with that power, the tunnel lights also went out, causing more panic and a race for some to get candles and matches down for lighting. (The raid was the 24th March raid of over 800 bombers flying over Berlin, with 72 being shot down and with losses of almost 400 Allies.)
Soon the lights returned and the escape continued until one officer got the signals wrong and exited when the signal was to stay concealed. An approaching guard saw the officer and no doubt both were near startled to death. Then a shot went off, no one was hit but four men were captured on the spot, with many still down in the tunnel waiting their turn.
Four men were captured at the exit point but 76 had gotten out and dispersed.
When word got back to Hitler he was furious. He had often bragged about the security of the camp and with egg still on his face re other escapes, especially the 132 in Austria, be ordered that every man caught was to be shot. He further order the cancelling of all off duty soldiers and called out well over 100,000 troops to find the POW's. Naturally all the barns in the area were also searched and from within many, POW's were huddled together to get a break from the cold weather and thus were caught. Others were caught at various points over the next few weeks.
Hitler also ordered that after each man was shot he was to be immediately cremated. His senior officers were outraged and argued that the most severe retaliations would come to them if the story ever got out. One proposed a far lesser number and finally the number of 50 from the 77 caught were taken one by ones and twos and told they were being taken back to Luft lll. Enroute they had a pit stop to allow the men to stretch their legs and relieve themselves. Then the Gestapo shot them in the back of their heads and ordered the local police to make the cremation arrangements. Some of the Gestapo were men who did not want to carry out the orders but realised that if they did not, they would be shot and their families probably rounded up and taken into prison. Some 27 officers were sent back to various POW camps including Stalag Loft lll
So the 50 were shot at various locations, the bodies then cremated and shipped back to the camp in Urns. These officers all aged between 21 and 45.
Of the 80 who exited the tunnel, only three made a home run and got back to England.

The above is probably a scene from the 1963 movie, while on the right is an image of the war crimes trial after the war and showing some of the Gestapo responsible for the shooting of the 50 Allied air force officers in their backs.
Shortly after the shootings the Germans put up signs in the camp saying that 41 POW's had been caught TRYING TO ESCAPE and were shot in the process. They then changed the number to 47 and finally to 50.
They also posted a notice warning the POW's that any further attempts may well end up with the same punishment despite being clearly illegal, and war crimes at that.
Here is that notice....

On Friday I will bring an update to this story some 70 years after the event.
Bart