At least 59 people were killed and 527 were injured in the mass shooting in Las Vegas

Instead of racing home after surviving the terrifying storm of gunfire that rained down on a country music concert Sunday night in Las Vegas, Lindsay Padgett returned to the venue to take shooting victims to the hospital in her pickup truck.

The Route 91 Harvest country music festival became the scene of the deadliest mass shooting in modern U.S. history when 64-year-old Stephen Paddock sprayed a crowd of 22,000 with automatic gunfire from the 32nd floor of the Mandalay Bay Casino before turning a gun on himself. Fifty-nine people died and more than 500 were injured.

“You see things like this on TV, but you don’t ever think it will happen to you,” the 29-year-old Las Vegas resident tells PEOPLE. “It was surreal.”

The night started out perfectly, says Padgett, who watched the concert from the front row with her fiancé, Mark Jay, her two cousins and three friends.

“It was a great night,” she says. “We were having a blast.”

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While country singer Jason Aldean was performing, she says heard popping sounds, then saw sparks and smoke.

“We were trying to figure out what it was,” she says. “Jason Aldean ran off stage and then everyone was yelling, ‘Get down!’ People were getting shot left and right.”

Unable to leave because they were so close to the front where it was packed with concertgoers, she and her friends huddled together on top of one another, not sure what to do.

“My friend kept looking at me and saying, ‘I don’t want to die,” she says.

Finally, when people near them were able to get up and flee, “we all just started running,” she says.

“I had called my mom to tell her that I love her and goodbye because I thought that was it,” she says.

She and her friends ran to a nearby airport hangar where they hid until they thought it was safe to leave.

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They went to get her pickup truck from a parking lot across the street from the venue when a man approached them, asking for help.

“This guy says, ‘We need your truck. We need to get people over to the hospital.’

I said, ‘Put them all in.’

They loaded the truck with five shooting victims – some in the cab and some in the flatbed.

“We were trying to get to the nearest hospital but the roads were blocked off,” she says.

They stopped when they saw an ambulance on the side of the road. Paramedics took three of the most critically wounded victims from her truck.

“My fiancé took out the kid who was shot in the back and he went to put him in ambulance,” she says. “The paramedics said to take him out right away. They said, ‘He’s dead.’ ”

After helping to load victims who were shot in the chest into the ambulance, “My fiancé picked up the guy who had died and put him back in the bed of the truck,” she says.

Another victim who had been shot in the leg stayed in the backseat of the truck. “Then we followed the ambulance to the hospital.”

After Jay helped the victims into the hospital, he and Padgett set out to return to the venue to try to help even more shooting victims. “We didn’t go right home. We wanted to go back to help more people. But so many roads were blocked off. We were having a hard time getting back there.”

So they headed instead to MGM Grand where her cousins were hiding.

While Padgett is relieved she and Jay were able to help the shooting victims, she says she will never forget this nightmarish night that stole the lives of so many.

“It was terrifying,” she says. “It was something that was out of a horror movie.”