Two helicopter crashes in Afghanistan killed 14 Americans on Monday, marking one of the deadliest days of the war for U.S. troops. In the west of Afghanistan, a chopper went down after leaving a firefight with insurgents, killing seven American troops, three civilians working for the government and injuring eleven troops, one U.S. civilian, and 14 Afghans. During another incident in the south, two U.S. choppers collided in mid-flight, killing four American troops and wounding two. Apparently, hostile fire did not cause the collision, although U.S. authorities have not yet given a reason for the first crash. A Taliban spokesman claimed that insurgents shot down a copter in the northwest province of Badghis, but it's unclear whether his as-yet-unverified claim referred to the same incident.