Boulder SWAT just trained in a real-life scenario that might just be every parent's worst nightmare.

Boulder Valley School District turned a soon-to-be demolished Douglass Elementary School over to Boulder County law enforcement to practice live ammunition and tactical training.

"It's very important and actually very rare that we get to use a structure that is realistic and relevant to what we do," said Commander Nick Goldberger, an assistant team commander with Boulder County Sheriff's Office SWAT. "We can shoot through a piece of plywood, but that's not realistic. Most schools have real doors, two-to-three inches thick of some sort of some material, whether they're metal or wood."

The sheriff's office shared some video with Next that showed deputies firing actual bullets through school doors and windows, and flash bangs and smoke grenades being tossed in hallways.

"We want to see how our smoke grenades work in that environment, and one of our concerns is that if we turn on our flashlights for the smoke, it's kind of like a snowstorm with the big flakes, you can't see," Goldberger said. "You're blinded. So, we're testing the equipment that we have to see which is best if you ever have that environment, and how to go through it in the most efficient way."

Longmont Police and the Boulder County Regional Bomb Squad also participated in the training. The Boulder Valley School District will demolish Douglass Elementary later this month and build a new school on the same site.