Witnesses to the Washington Navy Yard shooting Monday described being shot at by a silent gunman. Terrie Durham, a civilian employee in the Office of Naval Sea Systems Command, told NBC News she was in her third-floor office on the phone when an alarm went off around 8:15 a.m., followed by an announcement to leave the building. Someone told her, "this is not a drill," and as she was standing outside a door to make an exit, she saw a man with a rifle standing down the hall. "And he aimed at us and shot but missed, thank God," she said. Her co-worker Todd Brundivge said the gunman "said nothing." Another witness, Navy Commander Tim Jirus, told NBC News that a maintenance worker standing next to him was shot, and he took off running to safety.