As deputies -- who assisted with evacuations and held a perimeter until Orlando PD SWAT arrive -- got to the scene in the early morning hours of June 12, they were told that it was an "active shooter" situation and that there were "multiple victims" in the area who were "seriously injured with gunshot wounds," according to the report.
As soon as one deputy approached the scene, the first thing he saw was EMS tending to victims.
"The scene was chaotic as many of the victims had gunshot wounds and some who had been carried over appeared to be dead," the officer wrote in the incident report.
The officer was tasked with crowd control, he said, as several of the victims and witnesses were "hysterical." Victims who were fatally and critically wounded were being placed behind a nearby bagel shop and the wounded who were able to walk were placed in the parking lot.
A deputy who was positioned on the south entrance of the club saw three to four deceased victims in the parking lot, as well as several people exiting the building, the report said. When he saw a woman who was shot, he assisted an Orlando Police Department officer in moving her away from the building, he said. He then saw a second woman who had been shot and attempted to ask her about what she witnessed, but she did not have any information to provide, the officer reported. He then heard "numerous sounds of gunfire" inside.
While taking cover on the east side of the building just outside of the patio, one deputy described covering the other officers as they extracted injured victims from inside the club.
Another deputy described hearing shots fired as he approached the club on foot and seeing people covered in blood running out of the building and several more in the parking lot who suffered from gunshot wounds. That officer assisted in carrying the injured people to vehicles to be taken to the Orlando Regional Medical Center, the report stated.
A deputy who helped carry a man who appeared to have gunshot wounds to his right forearm and left shin remembered exactly what he was wearing: a black T-shirt and blue jeans. The officer then responded to the hospital after reports of shots fired there. When he arrived, he was advised by security that shots hadn't been fired and he positioned himself in the emergency room to assist with the hospital's lockdown protocol.
First responders have been grappling with the emotional toll of witnessing the aftermath of the worst mass shooting in recent American history.
"It was like a war scene," EMT Julio Salgado told ABC News earlier. "It was load and go. Just get them out of there."
Some officers have been hailed as heroes for rescuing wounded patrons as shots continued to ring out.
The shooter, Omar Mateen, pledged allegiance to ISIS during a call to authorities as the massacre was going on.