They called it the "neon sleepover." The Route 91 Harvest festival - three days of country music on 15 open acres in the middle of the Las Vegas skyline.
You could bring your kids, drink, dance and sleep in the RV park.
Country king Luke Bryan once called Route 91 an "adult playground," Rolling Stone wrote, and the lineup for its fourth year was "stellar."
A couple got engaged to the lyrics of High Valley's "Make You Mine" in the late afternoon, while electric fans blew mists of water into the crowd beneath the fierce Nevada sun.
Olympic champion Michael Phelps wrapped his arms around his wife. They had traveled from Arizona to catch the festival with friends, the Washington Post reported.
It was, Nicole Phelps wrote on Instagram, the "perfect #datenight."
Currently two days in. The 22,000 strong crowd are in good spirits.
"That was one of the happiest crowds that I have ever seen," he told his band after the show, and hung around to see his friend Hunt close out the second day.
The crowd pressed up against the main stage's fences that night, and the hotels shone like gems above.
"We can't believe we get to do it all over again," trumpeted the festival's official Twitter account.
Then tragedy struck.
SUNDAY
Inside one of those hotels, the Mandalay Bay Resort and Casino, a man with a gun waited and watched on the final day.
From his room on the 32nd floor, police said, he would unleash a stream of constant, rapid gunfire, leaving at least 59 dead and hundreds hurt in what may be the worst shooting in modern U.S. history.
And then he would die himself. But first, more than 20,000 people gathered below his window enjoyed one last day of music.
By evening, 21-year-old Taylor Benge sat drinking Red Bull vodka and margaritas.
He didn't really like country music, he told The Washington Post, but had recently gone through a breakup, and this was a way to distract himself.
So he sipped and listened as Kane Brown's set gave way to Big & Rich and the final acts of the weekend, and what he and many others would mistake at first for fireworks.
"We put on a show so people can have fun and forget about some of the day-to-day life things," Jake Owen, the night's penultimate act, later told Bones, who had played the day before.
"We live this life of not being scared," Owen told NBC's "Today" show after the massacre.
He made it through his set that night, and then walked onto the stage with a couple of friends to watch the festival's closing act - headliner Jason Aldean, who months earlier had been crowned entertainer of the year at the Academy of Country Music Awards just up the Strip.
Aldean was barely five measures into "When She Says Baby" when the shots started.
"Is that gunfire?" Owen remembered thinking, about 50 feet from the center of the stage.
The gunfire continued, steady against the beat of the song:
Owen said he could hear the gunfire ringing off the stage. "Pray to god," he wrote on Twitter. "Love you guys."
Aldean sprinted off the stage. Owen ran, too. So did other singers, workers and all the thousands of spectators - fleeing and screaming, falling and dying.