RADNOR, Pennsylvania (WPVI) -- The Nashville school shooting that left six people dead dealt yet another blow to a country weary of the senseless killing of children and teachers.
But in the emotional aftermath, the Nashville Police Department's response received praise.
It comes after the March 27 shooting that happened just before 10 a.m. that was captured on both surveillance and body camera video.
Video showed school shooter Audrey Hale arriving at the Covenant School. Ten minutes later, Hale fired the first shot, and just three minutes later the first 911 call is made as Hale canvassed the school.
SEE ALSO: Body camera video released from police who fired at Nashville school shooter; 3 kids, 3 adults dead
Body camera video captured the first officer who arrived on scene eight minutes later. You then hear a teacher who informed the officer that the school is on lockdown.
"A bunch of kids are upstairs," said the teacher.
Other officers quickly join and their body camera video shows the officers as they began clearing rooms. They hear gunfire on the second floor and immediately move to it.
"We've got one down. Keep pushing," said one officer.
Four minutes after arriving, officers killed Hale.
SEE ALSO: Nashville officers who rushed in to face school shooter speak out
"Those officers were fearless and stopped a lot of other lives from being affected or lost," said Radnor Police Chief Chris Flanagan.
Flanagan called the Nashville response textbook. He said the officers didn't hesitate and the arriving officers immediately worked to neutralize the threat.
"We go. We don't hesitate. We go with whatever we have," said Flanagan. "If we start to hear noise, we need to go to that if we hear gunfire in particular or screaming. We know to head to that location."
Flanagan allowed Action News' cameras to roll as Radnor police simulated a school shooting training exercise.
Like Nashville, Radnor officers moved in teams and navigated the halls and stairwells of an old abandoned school.
"This is a blank gun. So some of the officers will be able to hear where the actual bad guy is," said another officer.
They quickly take down the actor playing the suspect.
Radnor police tell the Action News investigative team they do three more in-depth training exercises a year, including one last month at Wayne Elementary School.
They practice the same techniques that largely all police departments follow.
"Our officers responded and within two and half minutes to three minutes of the first call we were able to neutralize the target," said Radnor Police Officer Ken Piree.
"A lot of the communication is when you approach a door, how we're going to enter the door. Talking about what they see ahead of them, any threats that may be behind them," added Radnor Detective Jamie Metzler.
Flanagan said all officers undergo this training. Since the Columbine High School shooting in April 1999, patrol vehicles are equipped with helmets, long guns and vests to protect against semi-automatic rifles.
Radnor has 13 schools and universities. Officers coordinate with schools about possible future responses.
In Radnor Township, first responders also use an app called CrisisGo. It allows officers who are responding on scene to communicate with teachers and administration inside the building. It also has maps of the layout.
The drill also included setting up a command center and coordinating with area hospitals and EMS as well as practicing communication with families.
"Parents that are arriving on scene," said Sgt. Brady McHale. "What are we releasing to them and when to make sure that they know that their child is safe is critical."
Nashville's police response was in stark contrast to the Robb Elementary School shooting in Uvalde last May where 21 lives were lost. It took officers 77 minutes to confront the killer.
Flanagan and others are reluctant to criticize but say training is critical. So rapid response happens because each second counts.
"Don't want to compare the two because I don't know them, but what I know is when I see a good job, we're going to identify a good job."