An Army psychiatrist facing deployment to one of America's war zones killed 13 people and wounded 30 others on Thursday in a shooting rampage with two handguns at the sprawling Fort Hood Army post in central Texas, military officials said. It was one of the worst mass shootings ever at a military base in the United States. The gunman, who was still alive after being shot four times, was identified by law enforcement authorities as Maj. Nidal Malik Hasan, 39, who had been in the service since 1995. Major Hasan was about to be deployed to Iraq or Afghanistan, said Senator Kay Bailey Hutchison, Republican of Texas. The victims, nearly all military personnel but including two civilians, were cut down in clusters, the officials said. Witnesses told military investigators that medics working at the center tore open the clothing of the dead and wounded to get at the wounds and administer first aid.