A U.S. official and a second person briefed on findings of a preliminary military investigation into a missile strike on an Iranian elementary school that killed over 165 people, many of whom were children, has been blamed for the attack. The bombing, if confirmed to be at the hands of the United States, could be among the highest civilian casualty events caused by American military operations in the last two decades. The incident has become a focal point of the war and has become among the top civilian casualties of the American military. A preliminary investigation has found that the U.K. Central Command used outdated data provided by the Defense Intelligence Agency for target coordinates, according to the person familiar with the preliminary finding. The finding prompted immediate calls for more information from the Pentagon. Dozens of Democratic senators have demanded answers from the Trump administration regarding the strike. The revelation could undermine public support in the US effort against Iran, potentially erode public support for the war.