Army Specialist Jonathan Pacheco, who returned from Iraq in May, described Fort Hood as a haven of sorts for soldiers who had been on the battlefront.
But after Army psychiatrist Maj. Nidal Malik Hasan allegedly opened fire on soldiers and others at the base, the troops at Fort Hood were forced to face the reality that even the home front can be violent.
"Everybody is on edge," Pacheco said. "Nobody was expecting it. Everybody thought they were safe."
Feelings of safety may indeed be a precious commodity at the base, located near Killeen, Tex. According to the website iCasualties.org, Fort Hood has suffered more in this decade than any other United States home base – 483 deaths in Iraq and more than 20 in Afghanistan.
Pacheco said everyone on the base is acutely aware of the losses overseas. But few of the troops likely expected this type of violence at home.
"Anybody who's been through this event today would need to be assessed in terms of evidence of any traumatic symptoms, there needs to be a follow up in some days to look at a bigger clinical picture," said Dr. James Griffith, professor of psychiatry and neurology at the George Washington University School of Medicine in Washington, D.C.
"If someone is showing symptoms [of PTSD], then I would advise against them against going into combat."
A senior military official confirmed to ABC News on Thursday that the unit that was at the readiness center at the time of the shootings was getting ready to deploy to Iraq. Col. Benton Danner, a media spokesman for Fort Hood, could not immediately tell ABC News what, if any additional counseling will now be provided to soldiers who were preparing to deploy and witnessed this event.
Dr. Paul Ragan, associate professor of Psychiatry at the Vanderbilt University School of Medicine in Nashville, Tenn., was deployed to Iraq in Operation Desert Storm, and has first-hand experience counseling troops who served there. He said that if orders for deployment to Iraq or Afghanistan are already in effect, it is unlikely that these troops will receive additional counseling before they go.
"When you're at that stage, you're assumed to be psychologically fit and suitable and ready to go," Ragan said, adding that the soldiers may be able to take advantage of PTSD clinics and other clinics abroad for soldiers once they're already shipped out.
But Dr. Marcia Valenstein, professor at the University of Michigan and a V.A. psychiatrist who works with the Michigan National Guard to help with psychiatric care for soldiers returning to war, said she believes some form of mental health services will be available to these troops.
She said she believes it is also important for these soldiers to rely on one another to help deal with the tragedy.
"My thought is they need to spend time together to process the event together, to have some time devoted to that issue, to also take part of the rituals that are going on down at Fort Hood," Valenstein said. "Part of this is being part of the community."
That may be particularly important, Ragan said, since soldiers at Fort Hood may suffer in different ways. In particular, he said, soldiers who witnessed the shootings might have survivor's guilt.
"That's one of the acute stresses: 'Why did that bullet hit and kill this person feet away, and not me?'" he said. He added that the fact that the massacre was committed by a fellow soldier could also be a factor.
"This was a caregiver," Ragan said. "The enormous betrayal... This was a man in uniform. This is a man who had been in the army for 10 years or more.
"This isn't some crazy person who had been coming off the street. This is an officer. He had been trained."
Specialist Pacheco, meanwhile, was fortunate on Thursday; he was on the other side of the base when the shooting occurred. But he said that while he still doesn't feel unsafe on his base, today's shooting will stick with him for a while.
"I'll be a little leery, on edge," he said. "I'll be a little more cautious from now on."