The fire broke out inside a home on Berkshire Road Tuesday just after midnight.
Alliance Against Homelessness of Bergen County, which operates the home, said four women in their 50's and 60's lived there.
Two of the residents died.
Here is video of the fire:
A Fair Lawn police officer fell off the roof while trying to help and was injured, but is expected to be OK. Another resident was treated for smoke inhalation.
A firefighter was taken to Hackensack University Medical Center with a leg injury.
"I saw smoke coming out of the second floor," said a neighbor, Steve Maiman. "I knew there were elderly people there, a group home, so I knew it could be a bad situation."
Police officers went in looking for the four women. Officer John Rovetto found one of them.
"I knocked on the door real quick and pulled on the door handle to see if it was actually open. It was and she was standing right in the living room," said Rovetto. "I pulled her out and said we need to leave."
Officials say the fire began in a second floor bedroom. Two of the women upstairs died in the fire. Another climbed out of a window and onto the roof. At the same time officers were still searching as best they could.
"We looked upstairs and they were fully engulfed," said Rovetto. "If any of us tried to go up there it wouldn't have worked out well for anyone. We checked the downstairs and made sure nobody else was downstairs. Then we came to the garage, opened the garage and found the bed frame."
That bed frame was used as a rescue ladder by the officers, as firefighters were arriving.
"Officer Rodriguez climbed up, pulled the woman from out of the window, we helped her down," said Rovetto.
Two of the women were taken to the hospital and are expected to be OK. Alliance Against Homelessness says the women were all independent and capable of getting around.
Two survived, thanks to seven dedicated police officers who risked their lives.
"We have great cops in the department, and I'm very proud of what they did last night," said Fair Lawn Police Chief Glen Cauwels.
The cause of the fire is under investigation. There is no indication of arson, said the Bergen County prosecutor.