Helicopter crashes killed 14 Americans on Monday _ 11 troops and three drug agents _ in the deadliest day for the U.S. mission in Afghanistan in more than four years. The deaths came as President Barack Obama prepared to meet his national security team for a sixth full-scale conference on the future of the troubled war, AP reported. In the deadliest crash, a helicopter went down in the west of the country after leaving the scene of a firefight, killing 10 Americans _ seven troops and three Drug Enforcement Administration agents. Eleven American troops, one U.S. civilian and 14 Afghans were also injured. In a separate incident, two U.S. Marine helicopters _ one UH-1 and an AH-1 Cobra _ collided in flight before sunrise over the southern province of Helmand, killing four American troops and wounding two more, Marine spokesman Maj. Bill Pelletier said. -- SPA
