NOV. 7, 1944 — a formation of American P-38 Lightnings on a routine patrol over Kosovo spot an inviting ground target: A column of enemy infantry and armour rolling through the open country. The Allied fighters streak down towards the vehicles with guns blazing. Enemy troops scramble for cover as the planes finish their first pass and come around for another run. The commander on the ground radios for help. A nearby formation of nine interceptors hears the distress call and speeds in to drive away the attacking aircraft. The P-38s break off their strafing run and a fierce dogfight ensues; both sides lose aircraft. After five minutes, the two sides with withdraw and the brief skirmish is over.
While a seemingly typical wartime encounter, there’s more to the story. Those ‘enemy’ ground troops that the American planes fell upon weren’t Germans at all – they were part of the Red Army. And it wasn’t Luftwaffe interceptors that flew to the rescue, but rather Soviet Yak-3 fighters. Most surprising of all, the American planes weren’t flying over German-controlled Kosovo at all. A navigation error put them 200 km away near Nis, Serbia — an area that had already been liberated by the Russians.  The entire affiar was chalked up to a case of “friendly fire” and swept under the rug. Yet sadly, the fatal air battle at Nis is just one of many examples of allies killing allies that, all told, cost thousands of lives during the Second World War. Here are a few more examples:
Operation Cobra – 136 Dead
Bad weather and a breakdown of communication led to the nastiest blue on blue disaster of the entire 1944 Normandy campaign. The incident sprung from an epic 3,000-plane Allied bombing mission aimed at annihilating German defences near St. Lo, France went awry on July 25. The plan, codenamed Cobra, originally called for British and American planes to drop their payloads as they flew east to west along the length of the enemy lines. Instead, the aircraft came in from the north and unloaded on both the Americans and Germans simultaneously. Low cloud cover prevented the pilots from spotting the friendly forces on the ground. Amazingly, the disaster was a repeat of a similar debacle that occurred only the day before in which 25 Americans were killed. Among the dead on the second day’s raid was Lt. Gen. Leslie McNair. He would turn out to be the highest ranking American officer killed in battle in the entire war (ironically a victim of friendly fire). Out of sheer rage, American troops knowingly opened fire on their own planes following the incident. 
Operation Bodenplatte – 237 Dead
The Luftwaffe’s last major air campaign of the war, which took place on New Years Day, 1945, was another friendly fire disaster. Planned to support the two-week old Ardennes Offensive (aka The Battle of the Bugle), the German high command scraped together the last remaining fighters and bombers for one final aerial blitz aimed at reigniting the stalled push into Belgium. The operation called for 900 aircraft to strike at British and American airfields in the region. Unfortunately, the plan was kept so secret that not even Axis units operating in the area were aware that it was taking place.  Assuming the planes suddenly overhead were British and American, German anti-aircraft batteries along the front opened fire on the planes. In all, 300 aircraft were destroyed and more than 200 pilots died. It was the largest loss ever suffered by the Luftwaffe in a single day. 
Incident at Mersa, Egypt – 359 Dead
Similar to the fiasco at St. Lo, a two-hour raid by RAF Wellingtons aimed at decimating the Afrika Korps in Egypt accidentally hit on elements of the British 7th Armoured Division and the 3rd Hussars, as well as some New Zealand troops. All told the error killed 359 and wounded 560. 
The Sinking of the Doggerbank – 364 Dead
Only one crewmember of the German blockade runner The Doggerbank survived that ship’s deadly March 3, 1943 encounter with the Nazi submarine U-43. The formerly British-owned 5,000-ton merchant vessel was back in the Atlantic after a long voyage from Japan and the Far East. On board were 7,000 tons of rubber and fish, along with the survivors of a German auxiliary cruiser and an oil tanker that both had been lost in the Pacific the previous year.  Somewhere in the South Atlantic, The Doggerbank was detected and followed by U-43. The crew of the sub, which knew the German ship might be in the area, wrongly identified the 400-foot-long vessel as a British cargo carrier. The sub fired a spread of torpedoes at The Doggerbank — three of the warheads struck home. In two minutes, the damaged ship was gone. A handful of crewmembers and passengers managed to board a lifeboat but darkness prevented the U-boat from rescuing any survivors. Over the coming days the small group would slowly perish from exposure, dehydration and even suicide, except one sailor by the name of Fritz Kurt. The lone survivor was eventually picked up by a Spanish ship and held prisoner until war’s end. The U-43 would herself be destroyed in July of 1943 and all of her crew would perish. 
The Allerona Train Disaster – 400 Dead
A railway bridge near the Italian town of Allerona was the site of one of the largest and most tragic friendly fire incidents of the entire war. A train pulling unmarked cattle cars containing 800 British, American and South African POWs had the misfortune of crossing a bridge north of Rome at the precise moment a squadron of American B-26s arrived to take out the strategic rail link. Amid the chaos of the bombing raid, the train’s driver stopped the engine in the middle of the bridge and fled on foot, leaving the prisoners locked in the cars. While some of the POWs managed to force their way out of confinement, more than 400 were unable to escape and were killed when the bridge took a direct hit.  None of the pilots had any idea that the boxcars was loaded with their own comrades.
The Cap Arcona Tragedy – 7,000 Dead
The Allerona train disaster pales in comparison with the Cap Arcona incident, which has been called history’s deadliest case of friendly fire. The disaster, which took place in the war’s final days (May 3, 1945), involved three ships in the harbour of Lubeck, Germany: the Thielbek, the SS Deutschland and the former luxury cruise liner Cap Arcona. Loaded with Allied POWs as well as more than 4,000 inmates from Nazi concentration camps, the luckless vessels were targeted by a flight of nine RAF Typhoons on an anti-shipping strike.  Allied intelligence believed the ships were carrying fugitive Nazis bound for Scandinavia when in reality, the Germans had loaded the ships with the prisoners and inmates and were reportedly planning on scuttling all three of the vessels, passengers and all.  As the British planes struck , the SS guards on board abandoned ship, but not before firing into crowds of panicking prisoners. Tugs and trawlers in the harbor managed to take 400 of the guards off the burning ships, but left the captives, many of whom leapt into the frigid water to escape the conflagration. Those survivors who didn’t either perish aboard the holed and sinking vessels or succumb to hypothermia, were repeatedly strafed by the Typhoons as they swam for safety. The British pilots later reported swooping low over the hapless fugitives firing into clusters of them as they bobbed in the water. Other prisoners were mercilessly cut down by SS guards as they neared the shore. The bodies of the victims choked the harbor and continued to wash ashore for weeks after the tragedy; skeletal remains were still being recovered as late as the 1970s.  Subsequent investigations suggested that the Swedish government had passed along intelligence to the British indicating the ships were housing prisoners and death camp inmates, but that information was never communicated to mission planners. 
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