Fire and Rescue NSW is investigating after a mother and her baby were forced to flee from their burning West Wollongong unit on Tuesday morning.
Emergency services were called to the Highway Avenue home after 11am, following reports the brick unit was well alight.
"The police were already in attendance when [firefighters arrived] and a young mother and baby were already on the landing of the unit and they were directed to clear from there," Fire and Rescue NSW Inspector Don Pescud said.
Fire crews took 20 minutes to extinguish the flames, before carrying out a search of the property to ensure everyone was accounted for.
"We're now waiting for our fire and investigation team to come from Sydney, who will assist our crews from Wollongong, along with the police, in investigating the cause and origin of the fire," Insp Pescud said.
"There is severe fire damage to the unit and considerable damage to the adjoining unit."
A Fire and Rescue NSW tanker, two pumpers and a rescue unit attended the blaze.