A calm and composed congressional intern who underwent basic nursing training while in high school said Monday that he knew that if U.S. Rep. Gabrielle Giffords was to have any chance of surviving her gunshot wound, he would have to stem the flow of blood coming from her head.

“I could tell she had a very severe gunshot but I was just trying do my best until emergency medical services could arrive,” Daniel Hernandez, 20, told TODAY’s Matt Lauer via satellite.

Hernandez and a handful of witnesses to a lone gunman’s shooting spree outside a Tucson supermarket are being hailed for their actions in the aftermath of the gunfire that transformed a peaceful Saturday morning political gathering into a scene of carnage and chaos.

When the shooting stopped, five people were dead. A sixth — 9-year-old Christina-Taylor Green — died on an operating table a short time later. Giffords and 11 other victims remained hospitalized, all in critical or serious condition.

Hernandez, who was trained in first aid and triage at a hospital as part of his nursing assistant class, said he checked the pulse and breathing of two or three victims before determining that the congresswoman was the most seriously wounded of the victims who were still alive.

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To keep her from choking on her own blood and to stop the flow of the blood, Hernandez sat her upright in his lap and applied pressure to her head wound until paramedics took over, he said.

‘Get the magazine!’
While Hernandez was attending to Giffords’ wounds, other bystanders were focused on the alleged gunman, 22-year-old Jared Lee Loughner. Retired Army colonel Bill Badger and a man named Roger Salzgeber tackled Loughner, according to the Tucson Sentinel, citing the Pima County Sheriff's Department. A third man, Joe Zamudio jumped on top of the suspect to hold him down. A woman, 61-year-old Patricia Maisch, grabbed a magazine out of the gunman’s hands as he tried to reload.

"Somebody said 'Get the magazine!' so I got the magazine, and I was able to secure that," Maisch told reporters Sunday. "That's what needed to be done."

Zamudio said he didn't really have time to think about what he was doing.

“I just heard something and I thought I could help,” said Zamudio, who was buying a pack of cigarettes when the shots rang out. “I tried to react as I could, as best as I could.”

Salzgeger has not commented on his role, saying only that he is "still dealing with it all," according to a report by ABC.

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After the gunman realized that he was overpowered, Maisch scolded him, but he did not say anything in return, according to Zamudio.

“We were all laying on him. He wasn’t going anywhere,” Zamudio told Lauer. “I felt like he was very cold. His expression was almost a smirk. He seemed like it didn’t matter.”

Badger, 74, was grazed by a bullet to the back of his head in the scuffle, but didn't realize it at first, according to the RepublicanHerald.com.

"While we had him on the ground I saw blood running and it wasn't until then I realized it was coming from the back of my head," he is quoted as saying. He was treated and has been released.

Steven Rayle, a physician who attended Giffords’ constituent gathering, was among those who held the gunman down. He told Lauer that after shooting Giffords, the gunman turned to look for other victims.

"I saw him as he shot her. And without hesitation he began spraying bullets randomly," said Rayle, who was just 10 feet away from the shooter when he starting firing. "He had additional ammunition. He seemed very determined and cold-blooded."

Loughner faces federal and state charges that could bring his execution if proven.