Taliban suicide bomber rammed a van into an armored NATO bus Saturday, killing 13 American troops and four Afghans in the deadliest attack on coalition forces in Kabul since the war began — a major setback for the U.S.-led coalition as it begins to draw down combat troops.
The explosion sparked a fireball and littered the street with shrapnel and twisted metal hulks. Heavy black smoke poured from burning wreckage at the site along the four-lane highway frequently used by foreign military trainers in the southwestern section of the city....