keywords: afghan afghanistan blast rubble exploded
text: Afghan Blast Has Alarming Implications  NAIK NAM, Afghanistan -- Saher Gul was chalking a long division lesson on the blackboard of his two-room village school. Twenty-five boys, ages 9 to 19, were sitting cross-legged on the dirt floor. Suddenly the earthen walls and ceiling exploded and collapsed, smothering the class in a mountain of rubble.