CORAL SPRINGS, Fla. – While the Broward Sheriff's Office has handled the forensic investigation into the Marjory Stoneman Douglas High School shooting last week, it was another police agency's officers that were the first to rush into the building to save those who had been shot.

About 130 cops from the Coral Springs Police Department responded to the shooting at the school, which borders the city and is about three miles from the station, Police Chief Anthony Pustizzi told Local 10 News in an exclusive interview.

Roughly 40 of those officers rushed into the building, where 23 victims were carried out to medics. Of those victims, 20 survived, the chief said.

Pustizzi commended Stoneman Douglas staff members, saying they were the first ones to try to help save students' lives. He also praised officers from numerous agencies who assisted in the effort, including two Broward sheriff's deputies who entered the building.

The BSO deputy assigned as the school's resource officer, Scot Peterson, resigned Thursday after learning he was under investigation for failing to enter the building while the shooting was underway.

Pustizzi said officers who did enter the building will need support after responding to the shooting and seeing things that "humans aren't meant to see."

"I've been a police officer for 30 years," Pustizzi said at a press conference following the interview. "You know, humans aren't meant to see this kind of tragedy, but the officers that went in there, the dispatchers that heard it, the firemen that treated the people -- you know, there's obviously a lot of support that needs to be given to them, as well."

By the time they stormed the building, the shooting had stopped, but officers didn't know the whereabouts of the gunman, Nikolas Cruz.

"I'm thinking, you know, this is a real one. You train for this day. You hope it never happens, but you only have one way and that's straight in, and you hope that a bullet doesn't find you, as well, but that's a possibility," Pustizzi said.

Pustizzi didn't need to go in. His officers were already securing the building when he arrived. He set up a command post in the parking lot, which turned into a triage center.

"All the training paid off," he said. "We did exactly what I would have hoped our officers did. They attacked the problem."

But Pustizzi said his officers, like so many others, are still dealing with the trauma of that day and some are receiving counseling.

"If you talk to the officers at Columbine, they'll tell you the same thing," Pustizzi said. "You'll never forget, you know, those kids, those teachers. They'll never forget what they saw."

During the news conference, Pustizzi also addressed reports about a tape-delay while officers were reviewing the school's security footage.

"There was a 20-minute delay," he said. "The delay never put us in a situation where any kids' lives were in danger or any teachers' lives were in danger. The delay was simply when we got there and the (Broward) Sheriff's Office and our officers and other officers from the community went into that building -- the key is to get as much intelligence as possible.

"The issue was more of a communication failure on who was reviewing the tape, letting other guys know that it was a 20-minute delay that they were reviewing. So as you can imagine -- you heard some of the dispatch tapes from the Sheriff's Office -- at first, the guys are hearing, 'Oh, he's on the second floor. Well, it's not true because we had people on the second floor."

Broward County Public Schools spokeswoman Tracy Clark said in an email that the school's cameras do have the ability to be viewed in real time.

"The surveillance system definitely has the ability to view the cameras in real-time," Clark said. "It also has the ability to view the recorded footage and replay footage from earlier in the day. During the immediate response to the event, the system was being viewed in real-time and the recorded footage was being viewed to retrace the actions of the shooter."

Clark said the district no longer has access to the footage, "as the server and all footage related to the incident was removed from the district's possession through a search warrant as part of the investigation to the event."

Broward County Sheriff Scott Israel said at a news conference he didn't know about the supposed security system delays, but would look into it.

Pustizzi said his police department will conduct in-depth reviews of their response to the shooting to make sure they learn from any possible mistakes.

"Anytime we have a serious event, we look at everything," he said. "We hawk it. We try to make sure that we learn from, not only our own mistakes, but anything that anyone else does so we don't repeat those mistakes."