Brendon O'Neal says the atmosphere at the concert in the minutes before the shooting began was extraordinary.
"Love songs were in the air, everyone was having an awesome time."
Then when the ambush came, the photographer - who was on the stage with the band - simply could not process what was going on.
He assumed there were an audio glitch and that the concert speakers were faulty.
Only when there was a third sustained burst of automatic gunfire did he realise that war had come to the legendary Strip of Las Vegas.
The rate of machine gun fire - a hundred bullet bursts in a few seconds - led him to compare it with the beaches of Normandy in 1944.
At least, he told me, it felt like a major battlefield ambush. He wasn't wrong.
High above him, armed with up to 19 weapons, the gunman was mercilessly killing people all around Brendon.
How he survived is a matter of pure luck, and it leaves him now with survivor's guilt.
The photographer is still in a state of visible shock.
Normally he takes pictures of surf competitors and hangs out at music concerts.
On Sunday night he filmed an atrocity and witnessed the worst massacre in modern American history.
"Ultimate evil was coming at you," he said, "and we had no idea where it was coming from. It was dark stuff out there. Evil in its purest form."