Outdated intelligence likely led to a deadly missile strike on an elementary school in Iran, according to a U.S. official and three sources familiar with the preliminary findings. The investigation found that an American munition was probably responsible for the strike, NBC News reported Friday, citing an American official and a person familiar with the preliminary findings, though the military is yet to formally conclude the United States is responsible. More than 170 people, mostly children, were killed in the Feb. 28 strikes on the Shajareh Tayyebeh elementary school in Minab on the first day of the U.S. and Israeli strikes against Iran, part of a barrage of attacks that also killed Supreme Leader Ayatollah Ali Khamenei. The ongoing investigation has so far found that the munition did not go off target, but rather hit the school because old intelligence showed it to be a military target, the four sources said.…