Sirens sounded at Ford Hood after a gunman opened fire killing 11 people and injuring more than 30 others.

Soldiers brought some of their wounded comrades to waiting ambulances as swat teams moved in.

Sources say the gunman responsible for the killings is Major Nidal Malik Hasan reportedly a psychiatrist and drug rehab specialist.

"A single shooter was shot several times,” said General Bob Cone. “However he was not killed as previously reported."

The suspect opened fire at Ft. Hood’s readiness center where soldiers who are about to be deployed, or are returning from Iraq and Afghanistan, undergo medical treatment. Hasan also gunned down people who were attending a graduation ceremony at a nearby theatre on the base.

Ft. Hood’s commander is stunned and says the motive is still under investigation. As the violence unfolded, frightened family and friends waited for word about their loved ones.

Ft. Hood, the world’s largest military installation and home to more than $50,000 troops, has been on lockdown.

President Obama was briefed on the shooting rampage and the casualties, many who are believed to be soldiers.

“It is difficult enough to lose them in battles overseas,” said Obama. “horrifying when they come under fire at a u-s base.”

The wounded have gone to several hospitals in the area. Many in the military community are wondering tonight how something like this could have happened.

Officials at Fort Rucker also released a statement earlier this evening expressing their deepest condolences for the families and friends of the fallen.