WASHINGTON — The absence of experienced senior leaders and inadequate action by officers in a tactical operations center, including a failure to provide effective artillery and air support, contributed to the deaths of five U.S. troops and nine Afghans in a Sept. 8 battle, an official investigation has found. Three unidentified officers from the 10th Mountain Division from Fort Drum, N.Y., received official reprimands following the inquiry into the clash, which erupted after Afghan security forces and U.S. Army and Marine trainers were ambushed in the Ganjgal Valley, near the border with Pakistan in northeastern Kunar province. "This event highlights...