FORT HOOD, Texas — The quiet, professional bearing of guards at this sprawling Army post's main gate Thursday provided stark contrast to the violent rampage hours earlier when a soldier killed three people and wounded 16 others before turning the gun on himself.
The Army said the gunman, identified by Rep. Michael McCaul, R-Texas, as Spc. Ivan Lopez, was an Iraq War veteran who was being evaluated for post-traumatic stress disorder, but had not yet been diagnosed for the illness.
Lt. Gen. Mark Milley, head of the Army's III Corps at the Texas post, said the shooter walked into a building in the 1st Medical Brigade at about 4 p.m. Wednesday and opened fire with a .45-caliber semi-automatic pistol. He then got into a vehicle, fired more shots from the vehicle, went to another building and began shooting, Milley said.
When a military police officer encountered him and drew her weapon, the shooter put his arms up before pulling out a gun and fatally shooting himself.
The tragedy came less than five years after this same post suffered the worst attack on a domestic U.S. military installation in history. On Nov. 5, 2009, Army psychiatrist Nidal Hasan went on a shooting rampage that left 13 dead and 31 wounded.
The Army base, dubbed "The Great Place," is home to two full divisions and 12 other units -- more than 40,000 soldiers. Parts of the nation's largest active-duty armored post resemble any typical suburban neighborhood. Such violence would seem totally out of place, although the streets bear names such as Tank Destroyer Blvd. and Hell on Wheels Avenue.
All physical training was canceled Thursday for soldiers, who were ordered to report to their units at 10 a.m. Chaplains set up family counseling centers at the Spirit of Fort Hood Chapel and nearby Scott & White Hospital.
Hospital spokeswoman Deontrea Jones said Scott & White had received eight wounded, including seven males and one female. All were in intensive care late Wednesday, three in critical condition and five in serious condition.
Outside the 24-hour Hallmark diner a few miles from the post, Terry Johnson and Anette Barreiro smoked cigarettes and fretted Thursday about the people they know at Fort Hood. The post is a major economic driver for the area, especially when it's a pay week like this one. Car dealerships, pawn stores and barbershops ring the base.
Johnson, 41, a car salesman, said some high-ranking officers have told him they feel safer deployed in combat zones than they do on their own post.
Barreiro, 48, a waitress at a nearby sports bar, said she had just come on duty Wednesday afternoon when the shooting happened. All the customers, she said, insisted she switch the TV screens to the news coverage.
"It's very disturbing that people could do something like this," she said between drags on her cigarette. "I know they've just come from war, but to do something like this..."
Inside the Hallmark, a sign promises free coffee to active-duty military. But Thursday, none were inside thanks to a post lockdown that had lasted late into the night, said waitress Catherine Wright, 34.
"It's been dead," she said. "Usually they come off the base and go to the clubs and then come here after, but not today." Wright, who was born on Colorado's Fort Carson, said she's always felt safe around military bases. But that's changed over the past few years, she said.
"You figure that since it happened before, they'd be more prepared," Wright said.
Officials did not say what might have motivated the shooter to kill his fellow soldiers and commit suicide. They do not suspect terrorism, but have not ruled it out either. He served four months in Iraq in 2011, Milley said, although NBC News reported that Lopez never saw combat there.
He was married and "does have family," Milley said.
"We do know that this soldier had behavioral health and mental health issues and was being treated for that," Milley said.
The soldier was undergoing treatment for depression, anxiety and a "variety" of other issues and was on unspecified medications, Milley said. He added that the shooter served four months in Iraq in 2011 and had "self-diagnosed" a traumatic brain injury.
"He was not wounded in action," Milley said.
Lopez arrived at the installation in February from another Army post and had not been assigned to one of the Army Wounded Transition Units, military units that are set up to care for wounded, injured or ill soldiers. Those assigned to these units have case managers who help them track appointments and manage their medical treatments.
Investigators are checking into whether Lopez had a criminal history, trying to learn more about the state of his mental health and his experiences in combat.
"All the things that you would expect us to be doing are being done right now," he added late Wednesday.
A federal law enforcement official told the Associated Press that investigators will interview the gunman's wife, search his home, and examine whether his combat experience caused lingering psychological trauma.
"We're heartbroken something like this might have happened again,'' President Obama said in Chicago, after being briefed on the events.
A statement from the White House said the Department of Defense with lead the investigation with support from the FBI and state and local law enforcement.
Contributing: William Cummings and John Bacon in McLean, Va.; William Welch in Los Angeles; Yamiche Alcindor in New York; The Associated Press