People run from the area at the Route 91 Harvest country music festival after gunfire rained down on the crowd on Oct. 1 in Las Vegas. (David Becker/Getty Images)

People lie on the ground covered with blood at the Route 91 Harvest country music festival. (David Becker/Getty Images)

Editor’s note: Quotes and captions have been edited for clarity.

“After capturing photographs of the final act of the Route 91 Harvest country music festival, I headed back to the media tent to start filing my photographs. After about 5 to 10 minutes I heard very loud popping sounds and I went outside to see what was happening and a security guy said it was just firecrackers, so I went back to work. The second time I heard the popping sounds, somebody said to me, “It was just speakers or sound equipment,” and again, I went back into the media tent. Then the noises went again, and that was when the crowd started to flee.

I went outside and saw a lot of people panicking and running for the exit that was right by the media tent. I grabbed my camera and went back outside and found a place where I could see what was happening and also [where I] wouldn’t be in the way of people, so I stood on a table and started to shoot — thinking to myself still, that this isn’t really happening, it’s just the speakers popping. It was so dark I couldn’t really see what was happening, there were a lot of people crying, speaking on cellphones and ducking for cover. As the crowd thinned out I was able to go a little closer to try to see what was going on and take some more pictures, and I’m still thinking to myself, “It’s just the speakers, there is nothing going on.”

There were groups of people helping each other everywhere and a real sense of people running for cover. People were fleeing, they were panicking. The gunfire was sporadic, it would stop and then more shots, then a lull and then more shots. I could hear people yelling at them to shut off the lights, to be quiet. People were cowering — they were very fearful for their lives. A woman tripped right in front of me, a man shielded a woman with his body before I saw them both get up and run away, a man in a wheelchair was helped to an exit. I was trying to capture anything that was moving and that had good lighting. That was critical, it was so dark and there was limited lighting. It was really hard to get a sense of what was happening. At this stage I still just thought it was a speaker popping, so I was trying to capture people’s emotions and a sense of the panic that was around me.

I went back into the media tent and called my colleague to see if he could find out what was happening, as I still didn’t know what was going on, and he said that he had found out that the police had called a Code Red and set up a perimeter. It was then I started looking at my photographs and what I was seeing was just unbelievable. It had been so dark outside I couldn’t see the details. I just saw a lot of people laying on the ground thinking they were playing possum, but now I could see people covered in blood and I thought, this is real. When I saw the image of the woman lying on the ground covered in blood, that was when the impact of what I was experiencing hit — when I realized people were dying.

I kept editing and filing my photographs; the power had been cut so I was working off the light of my laptop, until after 5 to 10 minutes everyone was evacuated and I was escorted to my car. I worked the rest of the night and into the morning capturing the police officers moving in and the wounded helping each other on the streets.

When I stop and think, it’s hard to comprehend what I witnessed. I was on autopilot, just doing my job capturing what was happening, which I think is important. Impactful images like these tell a story, they move people to think twice about doing anything like this. I’ve been doing this work for many years and it is instinct to photograph first and ask questions later. It probably seems irrational to just walk out and take pictures of people running for cover, but that is second nature for a photojournalist.”

People flee past a concession stand after gunfire erupted. (David Becker/Getty Images)

People scramble over fences seeking shelter from the rounds of gunfire. (David Becker/Getty Images)

People crouching near concession stands after a shooter opened fire on concertgoers. (David Becker/Getty Images)

People carry a wounded person from the grounds as an active shooter fired rounds into the crowd. (David Becker/Getty Images)

A man lies on top of a woman as others flee the Route 91 Harvest country music festival grounds. (David Becker/Getty Images)

A man in a wheelchair is pushed away at the Route 91 Harvest country music festival after gunfire erupted. (David Becker/Getty Images)

People crouch down as others run for cover. (David Becker/Getty Images)

Las Vegas police stand guard along the streets outside country music festival grounds after the shooting. (David Becker/Getty Images)

A cowboy hat lies abandoned in the street after the deadliest mass shooting in modern U.S. history.  The tally was 59 dead and more than 500 wounded from lone gunman. (David Becker/Getty Images)

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In Sight is The Washington Post photography blog for visual narrative. This platform showcases compelling and diverse imagery from staff and freelance photographers, news agencies and archives. If you are interested in submitting a story to In Sight, please complete this form.