Here are their firsthand accounts, as told to correspondent Dave Brooks.
Rob Frediani, building engineer from Half Moon Bay, California:
Before the final act, I was very close to the stage. And now thinking back on it, I'm like, if [gunman Stephen Paddock] would've chose to do it at an earlier time, I might've been in a worse situation than I am right now. But as it happened, there was a long -- I'd say maybe couple hundred yards from the stage -- there's a long bar that went right down the middle. I was standing in the middle of that bar to the left of the stage. And I heard the pop, pop, pop -- I thought it was someone doing firecrackers or something like that. Until I saw people ducking and screaming and running.
Then I got my buddy.... The images that I remember were turning to run towards the exit. But I saw shoes everywhere -- you know, people ditching their boots or their heels or whatever, just trying to get out of there. We made it through the exit. It went on for a long time. That guy got off a lot of rounds. A lot. As we got to the exit, it was still going on -- it seemed like it was going on forever.
There, I met up with a guy who was freaked that he was hit ... Pulled his pants down, [but] he was fine. And he handed me someone's cellphone. This girl in the chaos lost her cellphone. My phone, I was partying all day, and it was dead. Thank god I had her cellphone because I was able to kind of contact her. Later on, she let me use her phone to call my family and let them know we were safe.
After it happened -- it was so fluid -- I thought it was a terrorist attack and I could swear that I heard more gunshots because I called my wife right away. She said they were reporting there were multiple shooters in different hotels. We kept hearing them ... So my buddy and I ran across the street at that point to the Excalibur [Hotel]. And this is the crazy part. We went up there and we got into the food court area there and I heard a loud noise there. I don't know if someone dropped something. I don't know what it was, but people scattered. They ran [in] just every, every direction, like that.
So we ran up the stairwell and found an unlocked door. And we actually got on the roof of the Excalibur. We grabbed pipes. We locked the door behind us. We were both armed with pipes. We had no idea what was going on.
We were sitting on the helicopters and I called 911, let them know we were there.... It was like 45 minutes up there, then they came and got us. And we were taken to a ballroom area where there must've been four or five hundred people in blankets. All the hotels were on lockdown. So they had these blankets and pillows and things like that they were giving out. They kept us there for a good four or five hours. I didn't get out until it was like 4 in the morning. Then I went back to our hotel. We stayed at Luxor.
I had no clue [what was happening]. I didn't see flashes. I was very confident that it wasn't from inside [the festival] because they checked bags, everything like that. And I have to say, I mean, before that, it was like the most incredible vibe. I was high-fivin' people, hugs, you know, buying drinks. And it was just a trip because those people might be gone now. It's brutal.
I was complaining because I have this entrance thing on my wrist and I'm like, 'You think I'm gonna keep that on for three days?' Because you can't take that off. And now I don't wanna take it off. I wanted to remove it, but now for whatever reason, I just want to wear it, you know?
?Ty De Trinidad, teacher and father of two from Corona, California:
We were there enjoying the concert [on its] last day. Jason Aldean [was] doing a good job. And we heard shots -- it sounded like firecrackers, of course. And you were sure, you kept thinking, 'Where's the sparks?' And then Aldean stopped and you could see somebody told him on his earpiece to get off because you can see them just beelining out. And then we started hitting the ground.
One of my former students was next to me and he says, 'I've been hit.' I looked over and I didn't see any blood on him. [I was] just trying to check him. And, you know, a couple of girls, we covered them. The one next to us was bleeding. They said to everyone, 'Move down to the bleachers' ... Everybody shut their phones off and waited out ... You were just trying to get everybody out. People were going crazy.
At first, you just heard firecrackers and you're thinking, 'Oh, they're gonna put [on] a light show' ... And then all of a sudden, it's for real. I mean, this guy's looking at me going, 'It doesn't seem like a gun.' And I go, 'Well, I'm not exactly an expert,' but [we ran] and went down. As we went down, you saw [other] people going down. Then I saw the blood next to me. I had some on my shoes, had some on my arm. I'm like, 'This is real.' And in my mind, I kept saying that this was my time.
It was that real ... you know, because the kid next to me was hit. And I go, 'It's just a matter of time one of us gets hit.' And I just said, 'If this is it, please make it quick and swift' and thought about my two boys.
It felt like forever. They're saying about 10 minutes, but it felt like an hour.
Daniel Smith, environmental worker from Thousand Oaks, California:
It sounded like a bunch of firecrackers went off. And turns [out] it wasn't. I honestly thought it was a terrorist attack.... I thought they were on top of the roof, but it turns out the guy busted through the window, busted the hotel windows.
I ran, I hid in the middle side of the divider behind a palm tree ... that's why I'm all dirty. Then I ran into the Luxor to the bar and I made everyone go underneath the bar. It sounded like nobody knew where the shooter was and they're like, 'He's coming in!' But he's upstairs in the Mandalay, so [he] never came in. They blocked off the street, and that was it.
[Smith was then asked why he had blood on his shirt. "From a girl getting shot."]