Lying on the floor of his hotel room and wincing at the sound of gunfire, Ben Sweeney pecked out a text message to his wife, but did not hit send.
"Babe, I think someone is shooting here I'm really scared it's loud."
The gunfire sounded like it was coming from the room next door, Sweeney told The Washington Post. His mind raced to the worst possible scenario: An active shooter, kicking in doors, killing random hotel guests.
But the Mandalay Bay Resort and Casino is huge, and so is Las Vegas, and Sweeney didn't want to scare his wife - asleep back home in Pennsylvania - until he knew what was going on.
They had just said their goodnights. Sweeney was attending an IT conference that started the next day. He'd checked into the hotel around 6 p.m., walked around a bit and listened to the country music concert going on 30 floors below.
He opened the curtains, but instead of lights in the sky, he heard more booms, closer together, from the hotel.
"That's a machine gun," he thought, dropping to the floor. "An automatic rifle."
The booms were tightly grouped. Seven at a time. Five at a time.
"It seemed like I was so close," he told The Post. "I thought it was coming from the room next to me. I could hear the shots go off inside the hotel first, then echo outside."
He made sure his door was locked, turned off the TV and crawled into the bathroom. There, inside whatever safety the tub provided, he looked at his phone and hit "send."
Now, both Sweeneys were worried, but neither knew what was going on - or what to do.
Sweeney sent his wife a picture of the ground below the hotel, but it was too far away to show any detail. Then he sent her an audio file, but she couldn't really hear it.
His realization came a few moments later:
"Ya hun It's an active shooter I swear it's right in the room next to me."
At one point, "all of a sudden I hear this loud explosion," he told The Post. It was also from inside the hotel.
Police in Las Vegas said their SWAT team used explosives to get into the room where the suspected shooter, Stephen Paddock, had fired from.
Paddock was an accountant with real estate investments around Orlando and "plenty of money to play with," a family member said. He killed himself as SWAT officers closed in. The investigation into what has been called the worst mass shooting in the modern era is ongoing. On Monday, police were working to identify the dead.
coffee, leggings & a hoodie are life today. such a scary night.. I don’t even have the words to describe it.
Around 4:30 a.m., Sweeney was awakened by officers at the front door who said they wanted to do a welfare check. He assented and they burst in, checking the closets and the bathroom with guns pointed, clearing the room. When they left, he heard similar shouts and commands as the officers moved on.
By the time the sun came up, he said, the IT conference was an afterthought. He just wanted to be out of Las Vegas.
He booked a flight to Newark. His wife was going to drive 90 miles to pick him up.
Before he left the hotel, less than a day after checking in, he glanced outside the window. In the daylight, he could make out the police activity 30 floors below.
And he could see white tarps. There were dozens of them. Under each, he assumed, was a body.
"If I look out my window right now, I see the tarps out there. The aftermath. You see the tarps and you know someone went out there to have a good time in Vegas and never went home."