On Thursday, local, state and federal law enforcement officials descended on the small town of Prosper.
The town was selected about a year ago as one of five across the state to host a Coordinated Complex Terrorist Attack (CCTA) simulation.
For months, Prosper Police, Fire and Rescue, and Prosper ISD police have been working with the FBI, DPS, and Collin County agencies to come up with a day-long training.
“At 8:50 this morning, a call came into the dispatch center to the school dispatcher that there was some shots fired," said Doug Kowalski, Prosper Police Chief.
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Around 9:30 a.m., another call of shots fired at the Central Fire Station, he said.
The attacks were simulated right down to the injuries and casualties.
The goal was to test the readiness of first responders and communications crews as they try to respond to a coordinated statewide attack involving multiple agencies and overlapping jurisdictions.
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“That's why we have these types of exercises so that we can say we were ready to the best of our ability," Kowalski said.
That means overcoming a newly discovered challenge: Getting all agencies on compatible communication systems.
"We need that help that comes in that we're all able to talk to each other and communicate with each other. It's just the most important piece," said Prosper Fire Chief Stuart Blasingame.
The simulated attacks coincided with others in Lubbock, San Antonio, Houston, and El Paso.
They also ended up coinciding with real attacks that happened overnight in Maine.
“Heartbreaking. Absolutely heartbreaking," said Blasingame. "Again, none of us want to go to this. None of us want to see this. None of us want to hear about this. Unfortunately in our world, that's the facts. That's just what's going to happen."
"We hope that it doesn't happen here again in our North Texas area but drills like today are so important to make sure that if it does, that we're prepared," Blasingame added.
Officials say what happened in Maine was another sobering reminder of why their training was important.
“The response is normally going to be the same. So, what we did today was real life," Blasingame said.
And for some, like Chief Kowalski, a personal contact in Maine made the simulation that much more real.
"The first responder community is very much connected to each other," he said.