Hundreds of soldiers and personnel from the Fort Hood Army post in Texas gathered at a vigil Friday evening to mourn the victims and offer prayers for the families of Thursday's shooting rampage that left 13 dead and 38 wounded.
The Army's Chief Chaplain, Douglas Carver told the gathering to "remember to keep breathing...keep going," The Associated Press reported.
Earlier Friday, the caskets of 13 victims were loaded on to a C-130 transport plane for a flight to Dover Air Force Base in Delaware. Some 300 soldiers in dress uniform watched as the caskets were loaded onto the plane.
Shelia Casey, wife of the Army's top commander Gen. George Casey, attended the ceremony. She told ABC News' Charles Gibson. " It's an important ceremony, very moving, but important, " she said. "Rows and rows of soldiers there to bid farewell."
Gen. George Casey told ABC News' Charles Gibson that the attack at the U.S Army facility was "like a kick in the gut."
The suspect in the shooting, Maj. Nidal Malik Hasan, was transferred Friday to the Brook Army Medical Center in San Antonio. He is reportedly on a respirator, suffering from paralysis, although he is said to be in stable condition.
At a Friday evening news conference at Fort Hood, Army Col. John Rossi said the suspect fired more than 100 rounds, before being shot by a civilian police officer, Sgt. Kimberly Munley.
Neighbors said Hasan had been giving away his furniture and copies of the Koran over the last week, apparently disposing of his worldly goods, ABC News' Brian Ross reported.
Witnesses to Thursday's massacre at Fort Hood said alleged shooter appeared calm and shouted "Allahu Akbar!" ("God is Great!") before opening fire at a crowd of young soldiers, pausing only to reload before he was taken down by a female officer who is being hailed as a hero.
"It was very deliberate in his approach, they said that he was calm," Lt. Gen. Robert W. Cone, the base commander at Fort Hood, told "Good Morning America" today.
"He was shooting people more than once if he could," said Cone.
The Fort Hood Web site today addressed the tragedy with a line reading "Friday Is Day of Mourning! -- The duty day will begin no earlier than 0900."
Hasan used an FN Herstal 5.7 tactical pistol. The gun was purchased legally in August 2009 at Guns Galore in Killeen, Texas. Some law enforcement officials say the gun packs so much firepower that they call it "the cop killer."
A second gun found was a 357 Magnum Smith and Wesson revolver, but it is not yet clear if Hasan used the weapon during the shooting.
An army videographer who witnessed the shooting likened the event to a wartime battle.
"I felt like I was back in Iraq," specialist Elliot Valdez told ABC News' Terry Moran. "The noise, the chaos. It felt like Iraq."
Valdez was preparing to film graduation ceremonies in the theater when people started running in screaming, "Someone's shooting!" Then, a soldier in dress uniform for the graduation staggered in, shot in the back.
Valdez ran out and saw Hasan on the ground. "I thought he was dead," Valdez said. He did not realize that the man on the ground was the shooter until later. Valdez stayed focused and kept filming.
When asked how he felt about what he saw, Valdez struggled to contain his emotions.
"You see the bodies on the stretchers--that's tough, that's really tough," he said. "But Fort Hood families are strong. We pull together."
Victims of the shooting rushed to help others even before tending to themselves, said Cone.
"A young lady who had been shot in the hip and didn't realize it immediately took care of one of her buddies," said Cone. "She put a tourniquet on a soldier's leg and carried him out of the facility."
"Only after she had gotten her buddy taken care of did she realize that she herself had been shot," said Cone.
President Obama warned early Friday against "jumping to conclusions" regarding the motive for the shooting and ordered flags to be flown at half staff until Veteran's Day, saying that the "entire nation is grieving."
The president said he had met with the FBI chief to discuss the massacre.
Sgt. Salvatore "Rico" Sanchez told "Good Morning America" that he treated a captain who was nearby when the shooting started. Covered in blood that wasn't his own, the captain escaped unscathed with only a mild case of shock.
"According to the captain that I was treating, [Hasan] was sitting down and he just stood up out of nowhere and started shooting," Sanchez said.
As the sound of gunfire erupted, Sanchez said he heard people yelling to call 911 and "all kinds of cries for help."
Sanchez saw a virtual battlefield with dozens wounded and 13 dead or dying. Their names began to emerge today and each had a heartbreaking story. Among them was Francheska Velez, a 21-year-old soldier who had returned from Iraq three days ago because she was pregnant.
Velez was in the buildling filling out paperwork regarding her pregnancy when Hasan opened up.
Cone said Sgt. Kimberly Munley exchanged gunfire with Hasan and shot him four times despite being shot herself, putting a stop to the carnage.
"She was quite effective, one of our most impressive young policemen," Cone said. "She walked up and basically engaged him. I think, certainly, this could've been far worse."
Cone said Munley spent Thursday night calling her fellow co-workers from her hospital bed to make sure everyone was OK.
The atmosphere at Fort Hood Thursday seemed to be one of chaos, yet also one of quick action and sharp thinking. Numerous reports have described well-trained soldiers who used anything they could find to treat the wounded -- one witness told ABC News that a man's gunshot wound was treated with supplies from a mother's diaper bag.
"It is absolutely inspiring, the actions that soldiers took," Cone said today.
An Army official confirmed that Hasan would have been deployed to Afghanistan later this month, although officials previously said he was being sent to Iraq. Sources told ABC News that this would have been his first deployment.
Maj. Khalid Shabazz, who was Fort Hood's Muslim chaplain until a few months ago, told "GMA" he was "mortified" when he heard the news about the shooting and the person alleged to be behind it.
Shabazz said he had met with Hasan, one of 48 Muslim soldiers on base, on several occasions, and said that while Hasan and others sometimes complained about teasing from other soldiers, "I didn't find him to be depressed at all. I found him to be very pleasant."
Some of the Muslim soldiers, he said, "would complain about being taunted and harassed."
Shabazz said the taunts ranged from mild joking and misunderstandings to sometimes something more and could be "a real problem."
Hasan, who was reportedly upset about an upcoming deployment to Iraq, had been disciplined in the past for preaching to his patients about his Muslim faith.
Earlier in the day, Hasan had cleaned out his apartment, gave leftover frozen vegetables to a neighbor and called another to thank him for his friendship, the Associated Press reports.
Jacqueline Harris, 44, who lives with her boyfriend Willie Bell in the apartment next door to Hasan, told the AP that the alleged shooter had left a phone message on Thursday at 5 a.m.
Bell said Hasan had said it was "nice knowing you old friend. I'm going to miss you."
Hasan's cousin, Nader Hasan, issued a statement late Thursday.
"We are shocked and saddened by the terrible events at Fort Hood today. We send the families of the victims our most heartfelt sympathies," the statement read. "Nidal was an American citizen. He was born in Arlington, Va., and raised here in America. ... Our family loves America. We are proud of our country, and saddened by today's tragedy."
Hasan had reportedly recently hired an attorney to help him get out of the military.
According to the suspect's cousin, Hasan was also harassed after 9/11 because of his ethnicity, and was called a "camel jockey."
According to sources, Hasan, who is 39, attended the Uniformed Services University of the Health Sciences in Bethesda, Md, and later finished his residency as a psychiatrist.
In 2009, Hasan completed a fellowship in disaster and preventive psychiatry at the Center for Traumatic Stress.
He was promoted to major status in May, according to the Army Times.
According to Tthe Associated Press, retired Army Col. Terry Lee told Fox News that Hasan had expressed hope that Obama would pull troops out of Afghanistan and Iraq, and often argued with others who supported the wars.
ABC News' Ethan Nelson and Desiree Adib contributed to this report.