VIDEO: The Hartford Fire Department continues to rebuild.
It was short 100 firefighters after it lost more than that in 2016.
Now, nearly 40 percent of the city's firefighters are new.
"Five years ago, 19.5 [years] of experience was the average time for having a firefighter in the Hartford fire department," said Chief Reginald Freeman, Hartford Fire Department. "And today, that number is seven years."
The department lost 129 firefighters in 2016 following contract negotiations.
Freeman said his main concern with the unprecedented challenge was the department's ability to adequately respond to emergency situations.
It responded by creating a never-before-done aggressive professional development program, constant coaching, certification exams and classes.