ORLANDO, Fla. >> A scene keeps flashing through Officer Omar Delgado’s mind, sneaking into his slumber every time he closes his eyes to sleep.

It is of his first look inside the Pulse nightclub. Dozens of people were motionless on the blood-soaked dance floor, and the Eatonville police officer had just burst through the club’s patio door for a rescue.

“I yelled: ‘Hey, come on, get up! Let’s go! We have cover for you. Police! We’re here,’” Delgado said.

Nobody budged.

It took a moment for Delgado, 44, to realize that the “signal 43” he had responded to — Orange County police code for “Rush! Officer needs help” — was not an officer down, but a massacre of civilians.

Delgado, who had been working the night shift in a small town eight miles north of Orlando, was in the second wave of officers who responded after the initial shooting. He wound up spending hours inside, saving a few people and watching over the many dead.

“I thought they were playing dead so they would not get hit,” he said. “It wasn’t until I got my flashlight and scanned the room and saw so much blood from where all these bodies were lying. I looked to my left, to a guy who I guess got the worst end of it, and that’s when it hit me: ‘Wow, these people are all dead.’”

He arrived at the beginning of a three-hour standoff. Delgado dragged some of the wounded to safety and took cover behind a wall.

Delgado recounted a harrowing night of watching club patrons trip over corpses and writhe in agony as their bullet-ridden bodies were pulled across broken glass. The image of Brenda Lee Marquez McCool, with her shock of cropped white hair and tattoos, haunts him. He is among the group of responders who are likely to require counseling to find the will to return to work.

Officer James Hyland of the Orlando police is another. Hyland, who did two tours in Afghanistan, said what he saw at Pulse was worse. “It makes me forget about a lot of the stuff that happened in the military,” he said. “The situation was worse than being in a war zone.”

At a debriefing held at a local high school shortly after the shooting, many officers sat and cried, said Joseph Imburgio, one of the Orlando police officers who was on the scene at Pulse.

Officers from Newtown, Conn., to San Bernardino, Calif., have already learned these lessons, as they mustered the courage to ask for help.

“A lot of the departments are not sensitive to these issues and expect these officers to go right back to work like nothing happened,” said Eric Brown, a police union lawyer who represented officers who responded to the massacre of children at Sandy Hook Elementary School in 2012.

“If they do express trauma, they are considered weak and can get blacklisted in their assignments,” Brown said. “That’s why they don’t speak up.”

The U.S. Justice Department has recently begun funding programs to address the issue, said Pete Blair, a Texas State University professor who has studied mass shootings.

Delgado, a native of Puerto Rico who moved to Florida in the late 1990s, was responding to a disturbance in Eatonville when the first call for help went out.

He arrived to the sound of gunfire. He and two other officers ran into the club, fighting through the rush of survivors who were running for their lives. After a few minutes, some of the bodies started to twitch.

“They didn’t want to give up,” Delgado said.

The floor was slick with blood and officers said it was too difficult to keep balance while carrying a person.

“Imagine being low, trying to grab somebody and drag them out,” he said.

Angel Colon remembers.

“He grabs my hand and says, ‘This is the only way I can take you out,’” Colon, one of the three people Delgado saved, recalled at a news conference last week.

“I’m grateful to him, but the floor is just covered with glass. He’s dragging me out while I was getting cut.”

Delgado flashed his light in a woman’s face to temporarily blind her, so she would not look down and see that those were bodies she was tripping over. McCool, a mother of 11, was already dead, but he stayed by her side; some victims were shot in disfiguring ways, and he did not want that to happen to her.

“She was kind of my baby, per se, I was watching her,” Delgado said. “I knew she was gone.”

He sent an “I love you” text to his three children, in case it would be his last. He eventually left at 9 a.m., and sat in his driveway in silence for 10 minutes, trying to remember how he got home.

He cried once, when he surreptitiously attended a wake for McCool.

He got his first step toward closure when he visited Colon in the hospital. The men held each other in a tight embrace. “He needed a hug,” Delgado said.

“I needed it more.”

© 2016 The New York Times Company