Nine young boys gathering firewood in the mountains of eastern Afghanistan were shot dead by NATO helicopters who confused them for insurgents, according to a statement issued Wednesday by NATO. The incident, one of the worst cases of mistaken killings of children by foreign forces in the Afghanistan war, occurred on Tuesday, and the victims ranged in age from 9 to 15. Only one boy, 11, survived the attack. “We are deeply sorry for this tragedy and apologize to the members of the Afghan government, the people of Afghanistan and most importantly, the surviving family members of those killed by our actions,” said General David Petraeus, in a rare personal apology by the commander of NATO forces in Afghanistan. “These deaths should have never happened.” It was the third time in 10 days that the Afghan government has accused NATO of killing civilians.