Sixty-three U.S. troops have died so far this month in Afghanistan, making it the worst month for the U.S. in the nine years of the war. Three American service members were killed in two separate explosions, military officials said Friday. Military planners had warned of an increase in casualties when President Obama announced a surge in Afghanistan last December as part of a counterinsurgency strategy. June had been the worst month until July broke that grim record. The deaths of the two U.S. sailors who went missing a week ago in Logar, and whose bodies were recovered separately Sunday and Wednesday, remain a mystery, as the military is unsure why the two junior enlisted men were alone 60 miles from their base when they were captured.