Watertown City Fire Chief Dale Herman says he needs to hire more firefighters.
Herman told city council members at their meeting Monday night that between people leaving and firefighters off work, his department is about 18 people lower than it was five or six years ago.
That causes more overtime and more overtime can cause safety issues.
"I'm concerned about the amount of overtime that our personnel are working that it may become unsafe at some point in time," he said. "And it will be determined unsafe when the accident occurs."
Herman says last year the average firefighter was working more than five hours of overtime a week, but not every firefighter takes the overtime.
The city and firefighters' union have been in a long contract dispute, including a provision that requires a minimum number of 15 firefighters on duty per shift.