The Army psychiatrist accused of killing 13 of his colleagues here was transferred to a San Antonio military hospital on Friday while officials investigate the deadly rampage and try to prevent it from happening again. 'This was a kick in the gut,' said Gen. George W. Casey Jr., the Army's chief of staff, 'not only for the Fort Hood community, but also for our entire Army.' Neither Casey nor Army Secretary John McHugh revealed on Friday any details about 39-year-old Maj. Nidal Malik Hasan, believed to have been the lone person responsible in Thursday's shooting. Little was known about the extent of his injuries or possible motives in the shooting. What was revealed on Friday were stories of combat and of survival, all at a place that many call home. The moment the lone gunman opened fire on soldiers, after reportedly shouting 'God is great!' in Arabic, the crowd scattered. Several lay wounded in pools of blood. Bystanders ripped off their clothing and belts, making bandages and tourniquets. 'Every single medic was just going on like it was a movie, it was scripted: 'I need a shirt! I need a belt! Elevate his head!' Everybody was helping everybody,' said Jeannette Juroff, a 32-year-old reservist with the 75th Battle Command Training Division in Houston who was eating lunch at the Soldier Readiness Center when the shots began. 'It was amazing.' Juroff hid in a restroom with several others, the door locked and the lights out, while the screams grew louder and closer. A rush to help Not far away, Sgt. Andrew Hagerman was patrolling a residential area on the military's largest U.S. post when he heard a report of gunshots. At first, the 27-year-old military police officer from Lewisville and two-tour veteran of Iraq suspected kids with firecrackers. Racing to the scene, he looked at the man authorities say is responsible for the deadliest military base shooting in history. Hasan was shirtless, in combat pants and on the ground, wounded and unconscious. Nearby, 22-year-old Spc. Refugio Figuroa of Brownsville, on his way to the hospital with his wife for a sonogram, stopped his truck, jumped out, and directed traffic. Casey said that one soldier dragged four wounded troops to his pickup and drove them to Darnall Army Community Hospital on the post. Hasan was in stable condition late Friday at Brooke Army Medical Center, arriving by helicopter at 3:10 p.m., said spokesman Dewey Mitchell. He said Hasan was being watched by armed guards. Non-military security officers were stopping cars and checking IDs more diligently than usual at the Interstate 35 entrance to the San Antonio hospital, but no armed military personnel were visible around the building. FBI agents and armed guards on a second floor Intensive Care Unit corridor brusquely shooed visitors along. Hasan arrived in July Army records obtained by the San Antonio Express-News show Hasan was recently promoted to major and arrived at Fort Hood in July. Though reportedly an observant Muslim, he listed his religious preference as 'none' in the documents. Hasan, who had not deployed to the war zone but was preparing to go to Afghanistan, had served at Walter Reed Army Medical Center since 2004, said Col. Kimberly Kesling, who oversees more than 700 personnel as Darnall's chief of medical staff. Asked about Hasan's demeanor and bearing as an officer, she said he'd presented no red flags since coming to the post hospital last summer. 'As the chief of the medical staff, I am essentially his boss's boss,' said Kesling, a 46-year-old Boise, Idaho, native. 'I know Dr. Hasan, and as with all of my providers I keep track of them when they come into my organization and make sure that they're fitting in well with the medical staff, that they're providing good care to our patients, and our beneficiaries. 'By all reports, he was doing all of that. He was a hard-working, dedicated young man who gave great care to his patients.' Kesling said most of the injuries were below the torso a break for the hospital's ER teams because head injuries are far more difficult to treat. Reports of flashbacks Sgt. Howard Appleby, a 31-year-old Jamaican on his way to see a psychiatrist who is treating him for post-traumatic stress disorder, said he had flashbacks of his two Iraq deployments while taking wounded troops out of ambulances at the hospital. When asked to describe the flashbacks, he replied, 'I don't even want to talk about it.' Outside the hospital, he had performed triage on incoming patients, some of whom had driven to the emergency room on their own. More than half of them suffered multiple gunshot wounds. Most of the injured soldiers were young. The deluge of wounded took the hospital by surprise. Darnall had about 30 doctors, nurses and technicians when the first patients came in, but Kesling and Lt. Col. Larry Masullo said around 100 other staff quickly reacted, as envisioned in the hospital's mass casualty plan. But, he added, the hospital, though far from Baghdad or the facility he served in during 2007 in Mosul, quickly assumed a 'mass cal' event of the sort often seen in military medical centers in Iraq. 'I've been involved in several mass cals of this size while deployed but certainly didn't expect to see that here,' said Masullo, 46, and formerly of Farmingdale, N.Y. Armed with two pistols that were not issued by the military, Hasan is accused of shooting more than 40 people Thursday afternoon at the Readiness Center, filled with troops preparing to deploy to Iraq and Afghanistan or returning from combat. The assault lasted about 10 minutes, said Col. John Rossi, deputy commander of the post. Shots were still being fired as paramedics arrived and treated wounded, and one of them later suffered an 'acute stress response,' said Maj. Stephen Beckwith, a doctor and the post's EMS director. He said 16 trauma bays were available in the hospital, and medics and doctors treated patients quickly enough to never run out of beds. San Antonio Express-News staff writers Gary Scharrer and Scott Huddleston and Houston Chronicle reporters R.G. Ratcliffe and Lindsey Wise in Killeen, and Express-News staff writers Vianna Davila, Valentino Lucio and Guillermo Contreras in San Antonio, contributed to this report. 