Minutes after the shooting at the Las Vegas country concert began, first responders scrambled to the scene.
But some were already there.
Off-duty first responders in the crowd, like Robert Hayes with the LA Fire Department, had been attending the concert for fun. He was there with his wife and friends, and went from person to person in the crowd to see how he could help.
"If that was someone in my family, that's what I would have wanted somebody do for me," he said.
He described the scene as a war zone, with victims being helped by strangers.
"Everybody was coming together to try to work, I mean there was people sitting there that wouldn't leave people that were shot and they didn't even know them," he said.
Some had to improvise to get victims to the hospital, turning their personal vehicles into ambulances.
"There was a gentleman that was shot and he said, 'Can you help me?' And so I put him in my car and I had like six people in my car. People without shoes running just to get away," one driver said.
But in the midst of chaos, there was hope.
"Everyone's just communicating and working together, you got this person, you got this person, you got this person. It was completely horrible. But it was absolutely amazing to see all the people come together," said Vanessa, a nurse from California.
Some of the first responders also became victims. Several officers and firemen who were both on and off duty were shot. And an off duty Las Vegas police officer was killed.