FORT WORTH (CBSDFW.COM) – Police officers, firefighters and paramedics now train regularly on how to handle mass casualty threats. They often don’t know until the moment it happens, however, how it will affect them, and the impact can last for years.

Just one week ago, public safety agencies in Fort Worth practiced for a mass shooting scenario. And if someday a real one happens here, they’re at least prepared tactically for who to call, where to go and what to do.

“But when you’re on these scenes and it’s hard to even look at,” said Buddy Calzada with the Fort Worth Police Department.

“How do you prepare for that? This stuff’s almost impossible,” said Macara Trusty, with MedStar.

“I think it’s hard to understand how it’s going to affect you,” said Mike Drivdahl with Fort Worth Fire. “So I don’t think you can really gear up for it in training until the first time you really make one of those incidents.”

The public safety professionals all said the sense of losing – in a job where the aim is to save – can be as impactful as the graphic nature of any call.

They all have their career moments, that still sit with them

“I believe a 6-month-old, lost their life,” Calzada said, recalling a car accident.

“I still drive by that one particular area,” Trusty remembered. “There’s crosses on the road now”

At each agency though, the stigma of not being stoic about those moments, is changing.

“We started a campaign here, with our hope squad, that says it’s OK to not be OK,” Trusty said. “And I think we need to change that across society.”

“Anytime there’s something a little bit out of the ordinary, they’ll check up on this, and see if we need to talk about some things,” Drivdahl said.

It saves them from becoming a casualty of the career, so they can keep saving citizens from the next casualty that happens in the city.

“Because we don’t have to go home and share with our wives and our spouses or children what took place, but we’ve got to get it out,” said Calzada. “And when we have an outlet like that, it definitely assists us to answer the next tragic call.”