Paul Velez was a 20-year veteran of the New York Police Department before he came to Las Vegas. The UNLV Police Services detective was there 16 years ago at Ground Zero, a first responder to the Sept. 11 attacks.

When the call around 11 p.m. Sunday night abruptly woke him, he knew it was going to be serious. By 11:30 p.m., Velez arrived at the Thomas & Mack Center, where survivors of the Route 91 concert attack were pouring in, desperate for shelter.

“I hate to say, unfortunately, it wasn't new to me,” Velez said. “When I saw the looks on the faces, and saw some were injured, battered, and bruised from trying to get away. You saw injuries and the emotions on them, the trauma. I was definitely having flashbacks to that day.”

Campus police, Thomas & Mack workers, campus counseling service staff, students, and others from across campus were vital in turning the arena into a safe haven that night.

Carlos Soto is an electrician at the Thomas & Mack. He had gone to bed around 10 p.m., but sleeps with the television on. He had stirred around 11 p.m. when he saw the news. His first thought was for a friend, another electrician who used to work at the arena, who now worked the venue that was attacked. Soto texted him to make sure he was OK. He was, but the injury reports started climbing on the news.

Workers at the Thomas & Mack are able to use their phones to look at the cameras and control systems in the arena. Soto could see victims staggering into the plaza. He called his boss to get permission to come to the venue and help start distributing water and food from the stocked concession stands.

Soto woke his wife and gathered blankets. An Army veteran, he had an idea of what kind of condition the victims might be in. His daughters, including UNLV freshman Celine Soto, insisted on coming to help, too.

He only had around 30 blankets to hand out, and they went quick. Then Soto remembered the packing blankets covering furniture in the storage room. He got them from upstairs and started handing those out, too.

“Our concourse at Thomas & Mack, we always try to keep it chilled,” he said. “I knew the Mack was going to be an icebox for some of those people. A lot of [the blankets] are raggedy, but they didn't care. They just wanted something to cover with, or make a mattress out of it. For the first hour, hour and a half, that's all we did was pass out blankets.”

It was quiet on the concourse. People were in shock, looking for dark places to retreat to. Soto and other staff opened up suites for people who needed to collect themselves, alone.

UNLV police offered reassurance. “A lot of that came from the uniform presence — once they saw the police had the Thomas & Mack secure,” Velez said. “You try to speak to them as calmly and coolly as you can. You want to give them that sense that everything is going to be OK. The danger is over; they're safe.”

One man in the arena, Velez said, had been separated from his wife. He was distraught. Finally, a phone call came in. His wife was fine and had taken shelter when a family nearby had opened the doors to their home. Uber and Lyft drivers were offering free rides to anyone who needed to leave the Thomas & Mack.

“He didn't know if he could leave,” Velez said. He asked permission. “Of course you're allowed to leave. If you need to go, go. We got him down to one of the drivers and he got to go reconnect with his wife.”

Police Lt. William Newman was getting into bed when the first texts about an active shooter at Mandalay Bay started filling his phone. Immediately, a Metro captain called and asked to use the Thomas & Mack. The county’s designated Emergency Operation Center is normally the Convention Center, but the Thomas & Mack’s proximity to the south end of the Strip made it the venue of choice.

Newman arrived around midnight to find police and workers already at it. He was in charge of security at Centennial Park at the 1996 Atlanta Olympics when a pipe bomb exploded. Las Vegas response, he said, was efficient and organized, a sign of the extensive preparation that agencies across Southern Nevada go through.

Help came from all corners of campus. UNLV mental health professionals came to provide crisis counseling services. A conference room in Dayton Complex turned into as a makeshift shelter when five or six survivors found themselves on that part of campus. The Harrah College of Hospitality’s executive chef, Mark Sandoval, and two of his student workers got to campus early to bring breakfast over to anyone still in the arena.

“It seems like in times of tragedy and despair it helps you feel better helping others,” Sandoval said.