The shootings left 13 dead and 29 wounded. The alleged gunman, Maj. Nidal Malik Hasan (nih-DAHL' mah-LEEK' hah-SAHN'), was wounded by civilian police.
Gen. George Casey warns against reaching conclusions about motives until investigators have fully explored the attack. Early reports suggest Hasan, a Muslim, was angry about the wars in Afghanistan and Iraq and worried about his pending deployment to Afghanistan.
Casey appeared Sunday on NBC's "Meet the Press."