Eight fire engines and around 60 firefighters were called to a flat fire on London Road in Thornton Heath.
The whole of three roomed flat on the second floor flat in a six storey block was destroyed by fire. Half of the corridor on the second floor was also damaged by the blaze.
Ten people evacuated before the arrival of the Brigade.
Fire crews wearing breathing apparatus rescued two women and one child using fire escape hoods. Fire escape hoods provide members of the public with up to 15 minutes protection from four of the main fire gases (carbon monoxide, hydrogen cyanide, hydrogen chloride and acrolein). They were assessed on scene for smoke inhalation by London Ambulance Service and taken to hospital.
The Brigade was called at 13.00 and was under control by 1503. Fire crews from Norbury, Croydon, West Norwood, Woodside, Mitcham and Wallington fire stations were at the scene.
The fire is believed to have been accidental and caused by a tea light that was too close to combustible materials.