Daniel Hernandez had been U.S. Rep. Gabrielle Giffords' intern for five days when she was shot Saturday outside Tucson.

The junior at the University of Arizona was helping check people in at the "Congress on Your Corner" event when he heard gunfire. He was about 30 feet from the congresswoman. When the shots began, he ran toward them.

"I don't even know if the gunfire had stopped," he said Saturday night as he kept a vigil at the University Medical Center cafeteria, gathered near a TV watching tributes and getting updates.

When the shots began that morning, he saw many people lying on the ground, including a young girl. Some were bleeding. Hernandez said he moved from person to person checking pulses.

"First the neck, then the wrist," he said. One man was already dead. Then he saw Giffords. She had fallen and was lying contorted on the sidewalk. She was bleeding.

Using his hand, Hernandez applied pressure to the entry wound on her forehead. He pulled her into his lap, holding her upright against him so she wouldn't choke on her own blood. Giffords was conscious, but quiet.

Ron Barber, Giffords' district director, was next to her. Hernandez told a bystander how to apply pressure to one of Barber's wounds.

Barber told Hernandez, "Make sure you stay with Gabby. Make sure you help Gabby."

Hernandez used his hand to apply pressure until someone from inside Safeway brought him clean smocks from the meat department. He used them to apply pressure on the entrance wound, unaware there was an exit wound. He never let go of her.

He stayed with Giffords until paramedics arrived. They strapped her to a board and loaded her into an ambulance. Hernandez climbed in with her. On the ride to the hospital, he held her hand. She squeezed his back.

When they arrived at the hospital, Hernandez was soaked in blood. His family brought him clean clothes because the FBI took his for evidence.

He waited at the hospital while she went into surgery. He needed to tell police what had happened. He overheard people walking by talking about how Giffords had died. He also heard this on NPR. Later, he learned she had lived.

"I was ecstatic," he said. "She was one of the people I've looked up to. Knowing she was alive and still fighting was good news. She's definitely a fighter, whether for her own life, or standing up for people in southern Arizona."

The fact that Hernandez was nearby and able to react quickly probably saved Giffords' life, said state Rep. Matt Heinz, D-Tucson, and a hospital physician. He talked to Hernandez at the hospital after the shooting.

Eight hours after the shooting, Hernandez stood with Giffords' friends and staff and told them what had happened. The tall, strong 20-year-old said, "Of course you're afraid, you just kind of have to do what you can."

They hugged and thanked him. Later, he sat with his mom and sisters and told them about his friends and the staffers who had died that day.

"You just have to be calm and collected," he said. "You do no good to anyone if you have a breakdown. . . . It was probably not the best idea to run toward the gunshots, but people needed help."