SOUTHINGTON, Conn. (WTNH) — It was strange to see an E.R. nurse dressed up in fatigues, but Friday was no ordinary day at the office for Nurse Evanna Burgwardt.

She, and other nurses and E.R. workers at St. Mary’s Hospital in Waterbury spent the day learning what it takes to function if there’s ever an active shooter at their hospital, or at a public event. In Friday’s drill, they were trained by the crew at King 33.

The workers went around hallways with police officers, protecting themselves from a mock active shooter, while trying to find injured “victims”, and give them the medical care they needed fast with danger going on all around them.

The goal is to save lives in the toughest of circumstances. Chris Fields was one of the people leading the training. He was a member of the U.S. Army Special Forces and now owns King 33. He started his company and this type of training so he and others could lend their military expertise to first responders dealing with trauma situations and acts of domestic terrorism and active shooter situations.

Fields described why it’s so crucial for first responders to learn these techniques.

You could actually be in a situation exactly like the Boston bombing or Newtown where you are going into a hot zone and you are exposed to the active threat, but you’re still treating people.”

During the drill, they try to make it as chaotic and as stressful as possible.

“It is scary and intimidating, which is why training is so important,” said Nurse Burgwardt.

“If we can simulate that in training, the first time they go into that situation in real life, they’re not as stressed out or shocked, they can go right to work with all of their skills and knowledge,” said Fields.

The drill is part of a 3-day training event called “Tactical Combat Casualty Care” (TCCC).

“It’s great to know what to do when people’s lives are in danger and when there’s danger for you trying to help people,” said Nurse Burgwardt.