LAS VEGAS -- When Air Force veteran Jay Purves first heard the pop-pop-pop at the Las Vegas country music festival, he knew immediately it was gunfire.
Purves and his colleagues at a private security firm manning the Route 91 Harvest festival Sunday night were a force of 200 unarmed first responders who lifted people over barriers, hid them behind pillars and under the stage, and funneled them to exits amid the panic.
One of the Contemporary Services Corporation guards died and two were wounded when a gunman on the 32nd floor of the Mandalay Bay hotel casino across the street opened fire on the outdoor festival, killing 58 people and injuring nearly 500 others.
Now, despite the fresh trauma and losing one of their own, many of the company's guards - "the yellow shirts," Purves calls them - are returning to work this weekend.
Supervisor Cheryl Metzler put on her uniform Friday to work a UFC weigh-in, her first event since the shooting. She was anxious but stayed composed until it came time to thank other CSC guards who came in from out of state to help.
"I kind of broke down a little bit," she said.
Purves, the vice president of CSC's Las Vegas branch, said private security guards are not always taken seriously because they aren't law enforcement.
"We're the ones often in the background, in the shadows, but we were actually the ones right there in the thick of it all," he said.
The staff has worked events at the venue before and was already reeling a bit from Saturday, the second night of the festival, when a drunken attendee punched one of their guards in the face.
Metzler was working Sunday in a command center that resembles a shipping container, watching the concert on seven large surveillance monitors, when someone called to ask if there were supposed to be pyrotechnics at the show.
"We thought fireworks," she said of the popping sound. "But then it kept going."
As people began to flee, the guards fanned out across the venue, coaxing shell-shocked concertgoers too frightened to move to head to a safer spot.
Early in the chaos, Purves got a call on his radio: "Erick's been hit and is down," referring to 21-year-old employee Erick Silva.
Silva, assigned to the front of the stage, off to the side where the soundboard was kept, was shot in the head while helping people climb over a barricade.
Purves started running to him. On the way, he got another call on the radio. A second guard, Jeff Bachman, who was moving Silva away from the stampeding crowd, was shot in the leg.
As the gunfire continued, Purves and the other guards got hold of a bicycle rack, flipped it on its side and used it as a gurney to carry Silva, who was gasping for air. They carried him out to emergency responders before running back in to continue the evacuation.
"It was complete carnage and chaos," Purves said.
Metzler and others were trapped inside the command post, watching the screens in horror as more shots rang out.
"What I had seen on those TVs - no one should ever see in their life. But I wish everybody could have seen what I'd seen with our people," she said. "Our people, they didn't run."
Another guard, Daniel Rascon, was shot in the arm while trying to get people in wheelchairs off a ramp.
"It was hard, seeing my people out there, not being able to help them," Metzler said. "But then they knew I was in there and they would call me on the radio and I was trying to comfort them."
The guards are still shaken, Purves said. But many will be going out again this weekend to work security at major events in Las Vegas - including a lantern festival and the UFC event.
Purves credits police, firefighters and other first responders with helping save lives Sunday. But the private security guards, "they're the forgotten ones," he said.
"These are working men and women who make 10, 11, 12 bucks an hour, who are in the thick of everything and have to deal with intoxication, evictions, fake tickets, complaints that the beer is too hot and the hot dogs too cold," Purves said. "The yellow shirts are the ones people go to for help."
Silva, who worked for CSC for three years and dreamed of becoming a police officer, died Tuesday from his wounds.
The company is offering counseling to its employees and helping Silva's family arrange a funeral. Some guards are taking a break to deal with the trauma. Many others, including Purves, decided to go back to work and are staffing their first events this weekend.
Metzler isn't sure when her next day off will be. She said she's glad to be back with a group she considers family.
"I want to be with my people to talk about it. If I'm just sitting home, I'm watching the TV and I don't turn it off," she said. "So this is the best therapy and the biggest reason I wanted to come back."
Watson reported from San Diego.