LAS VEGAS — Seven hours into a normal shift on Sunday night, Las Vegas Police Officer J. Van Dyke said he heard the radio broadcast about an active shooter at the Mandalay Bay Hotel.

For the next 11 hours, he says stress and anxiety were among the most common emotions.

Officer Van Dyke wrote a Facebook post after his 18.5-hour shift that’s giving tens of thousands of people a glimpse into what it was like for the first responders who worked during the worst mass shooting in modern US history Sunday night in Las Vegas. At least 59 people were killed and more than 520 others were injured.

Officer Van Dyke wrote a Facebook post after his 18.5-hour shift that’s giving tens of thousands of people a glimpse into what it was like for the first responders who worked during the worst mass shooting in modern US history Sunday night in Las Vegas. At least 59 people were killed and more than 520 others were injured.

“Listening to the radio while we were headed towards the Mandalay Bay, listening to the stress in my partner’s’ voices, listening to them shouting about how many victims they saw, the fact that shots were still being fired,” he wrote. “The chaos of not knowing where the shots were coming from, or who was shooting them. The fact that it was a fully automatic weapon, machine-gun style….Whoever this was, he outguns us.”

While he was still miles away from the scene, Van Dyke said he heard gunshots on the radio and his partners asking for help. It’s something no cop ever wants to experience, he wrote.

Once they got to the scene, Van Dyke said they still didn’t know where the shots were coming from and said they were learning vague details from several panicked 911 callers. Some of them were reporting multiple shooters in several different hotels.

But he says the ongoing radio traffic about finding victims and shots being fired didn’t compare to seeing the faces of people running from the scene.

“The citizens and tourists we all swore to protect, running for their lives, hoping that we could give them a miracle,” he wrote.

Officer Van Dyke also admitted it was frustrating for the officers when people questioned them and asked why they had to leave their hotels, saying he felt that some people didn’t understand the magnitude of what was happening.

“But all those negatives are forgotten when you find a crying, terrified family sheltered in place inside a bathroom stall. When you get to guide a horrified mother and her crying child to safety,” he wrote.

But he says the most powerful and one of the most important aspects of the massacre was seeing the bravery and courage of first responders “that only we get to witness and fully understand.”

He says one of his coworkers was on vacation but when he heard what was happening, he suited up and showed up to help.

“In my 12-man unit, only 9 of us were ‘on-duty.’ The other three came from home when they heard what was unfolding,” he said. “At the end of the day, we fight side by side, and we go in together.”

Van Dyke said he would honor the more than 50 people who died, and asks everyone, “for one day, to put your politics aside.”

“Forget about Donald Trump. Forget about the NFL. Forget about whether you should stand or kneel,” he wrote. “Forget about our differences in opinion when it comes to policing in America, and how cops treat their communities. Let’s come together as a UNITED nation, and honor the victims and their families. Let’s come together as a UNITED nation and honor the first responders who worked incredibly long and stressful shifts, without food, water, or even bathroom breaks.”You can read Officer Van Dyke’s full post here:

After his post went viral, Officer Van Dyke wrote a second post saying he was, “humbled that so many in this great nation still support the mission of Law Enforcement.”

“I appreciate the overwhelming support that you have shown the family of Law Enforcement more than any of you know,” he said.