Law enforcement and emergency responders participated in an active shooter drill at a Pinellas County Elementary School on Wednesday.By Casey Albritton

CLEARWATER, Fla. (CW44 News At 10) – Law enforcement and emergency responders participated in an active shooter drill at a Pinellas County Elementary School on Wednesday.

It involved multiple agencies and has taken three years to plan.

READ MORE: Trump says he took the Fifth in questioning in New York Attorney General fraud investigation

“It’s going to happen again. The question is when and where,” said Pinellas County Sheriff, Bob Gualtieri.

For first responders in Pinellas County, their Wednesday started with the sound of gunshots.

“Stopping the horror. As soon as you possibly can. That has to be hands down, unequivocally the number one priority,” said Gualtieri.

That’s exactly what emergency crews were doing: responding to an active shooter drill that looked as real as it can get.

“You saw the deputies going through windows, you saw the firefighters and EMS personnel going through windows and carrying out causalities,” said Gualtieri.

READ MORE: Gabby Petito's Family Seeks $50 Million From Utah Police Department For Inadequate Response To Brian Laundrie's Abuse

Agencies across Pinellas County knew there was a drill, but didn’t know specifics on how many shooters there would be, how many victims, or where everyone would be at High Point Elementary School.

“You’ve got casualties, you’ve got people screaming, you’ve got wounds, you’ve got Fire EMS components and task forces, and trying to get people out. You have to put stress on people to simulate it the best you can,” said Gualtieri.

Gualtieri says the fake shooter was caught and victims received medical help.

“These types of situations, we all fear them, we don’t want to see them in Pinellas County Schools but we must be prepared,” said Pinellas County Schools Superintendent, Kevin Hendrick.

The sheriff’s office will release a report in a few weeks describing how local emergency response agencies could do better.

MORE NEWS: The FDA Authorizes Change In How Monkeypox Vaccine Is Given

“I saw things today, and it will all be a part of the after-action but we’re learning and closing that gap so if the real thing does happen, we are in the best possible place,” said Gualtieri.