Four fire engines and 21 firefighters and officers attended a fire at a house on Lonsdale Avenue in East Ham, this morning.
An adult and four children escaped the property before the arrival of the Brigade and three people were taken to hospital suffering smoke inhalation.
Most of the ground floor of the property was damaged by fire.
Firefighters from Barking, Plaistow, Stratford and Shadwell fire stations attended incident.
The Brigade was called at 1120 and the fire was brought under control at 1222. The cause of the fire is under investigation.