People who live in the 24 apartments directly above the parking garage where the fire started will not be able to return for several days.
A structural engineer need to inspect the building to declare it safe.
"Very unusual. There was heavy black soot. " says Firefighter Ernie Robb describing the blaze. " We believe there are a lot of tires down there that were burning, a lot of nasty stuff".
Relying on thermal imaging cameras to be their eyes, firefighters tracked down the hot spots.
"At the one hour, 40 minute mark they declared that the fire is totally out" says Nick Craig, Green Bay Fire's Public Information Officer.
100 firefighters were on scene from at least nine local departments.
"We rotate" Robb explains. "We have a bottle of air, when our alarm goes off that we are on low air we come out here and rotate. We follow the hose back out and the crew reliving us follows the hose back in".
This fire gave Green Bay crews the first chance to use a new piece of equipment, a hydrogen cyanide monitor.
The sensor detects the dangerous gas that is created when certain materials, especially plastic, burn.
It is an addition to carbon monoxide detectors the department already uses.
"Having this device makes certain it is a safe place for fireman and that we are letting people back into an environment that is safe" Craig explains.
In addition to the challenging fire, crews were also challenged by the weather.
"I am sure some of our people did take a tumble today with the ice rink we are working on. Thank goodness we had public works doing a lot of salting to prevent those falls" says Craig.
According to fire officials the roof of the garage, is made out of concrete which likely helped contain the fire.
The official cause of the fire is not known yet.
Investigators are focusing their efforts on a car in the garage.