(UPDATE) Twelve shot dead and two to three dozen wounded at Ford Hood, Texas, the largest U.S. military instillation in the world. Perhaps as many as three shooters. One assailant, an Army officer, was killed. The Houston Chronicle reports:

... Most of those killed were also soldiers, according to the briefing by Lt. Gen. Robert Cone, the post commander. One shooter was killed and the other two were in custody, he said.

Cone said that local police responded relatively quickly and killed one of the shooters. He said he believed that one Fort Hood civilian police officer was among the dead. Fort Hood has contract and military police, he said.

"This is a terrible tragedy," Cone said.

ABC News identified the dead assailant as Maj. Malik Nadal Hasan of Virginia.

President Obama, speaking in Washington, called the shootings a "horrific incident" in his first public comments:

... It's difficult enough when we lose these great Americans in battles overseas. It's horrifying that they should come under fire at an Army base on American soil.