A Watertown City Firefighter was treated on scene and some tenants needed to be rescued from an apartment building fire early Sunday morning. According to Watertown Fire Department officials, crews arrived on scene just after 2 AM to find fire coming out of two windows on the first floor and heavy smoke throughout all 3 floors of the building at 138 West Main Street. Officials say crews made an aggressive push into the building and had to assist trapped occupants on upper floors to get out of the building safely. All tenants were able to do so unharmed. Two dogs and numerous cats were also rescued. A city firefighter was treated on scene by Guilfoyle Ambulance for over exertion, and later in the day, fire officials said he was doing okay and has been released back to work.