At 17:25hrs the Southbury Fire Department was alerted to a house fire on Roxbury Road. Assistant Chief Bob Barnes arrived to find heavy fire issuing from the garage end of a 5000 square foot house. A request for additional assistance went out for the Roxbury VFD, Woodbury VFD, the Sandy Hook VFD, Middlebury VFD, and Oxford VFD. A transitional attack was mounted from Southbury Engine 4 utilizing CAFS and two hoselines. While the fire attack was underway, a tanker shuttle was initiated with Oxford Chief Pelletier as the Water Supply Officer. Once the main body of fire was knocked down, an aggressive interior attack to the second floor began. This crew knocked down a lot of fire stopping most of it from getting into the main living space. While operating, the garage with a second floor bonus room suddenly collapsed. Command ordered an evacuation, PAR, and reset of all operations. With no one missing or injured, the fire attack continued. The fire was contained within an hour. All firefighters went through Rehab conducted by Roxbury EMS Rehab, assisted by Southbury, Oxford, and Woodbury EMS. Two firefighters were transported for heat related issues and were released. The Southbury Fire Marshal and Connecticut State Police Fire Marshals are investigating cause and origin.