A house in Yeovil Drive Bomaderry was destroyed by fire at 2.15am Friday.
Two people were taken to Shoalhaven Hospital, one suffering smoke inhalation the other believed to have burns to their hands.
Firefighters from Nowra and Shoalhaven attended the fire.
Station officer Sean Doohan said the fire quickly spread from a garage into the roof space of the house.
“We got the call at 2.15am and we arrived at the fire 12 minutes later,” Mr Doohan said.
“On arrival we were able to ascertain all occupants had evacuated. Ambulance officers were taking care of them.”
“Being a fire in the roof space a lot of the damage is up there, however the roof did start to collapse.
“We managed to extinguish the fire and protected the neighbouring house,” he said.
Police investigations will continue Friday morning.