Five fire crews yesterday tackled a blaze at a top-floor flat in Chain Street in Bradford city centre.
The blaze broke out shortly after 11.30am when smoke was seen billowing from the roof of the building.
Three ambulances also attended the scene with at least one person taken to hospital for treatment for what is believed to be smoke inhalation.
The aerial appliance brought the smoke under control at about 12.30pm. Damage could be seen to the roof and back of the flat.
The cause of the fire was under investigation last night.
The flat affected was not one of those which had undergone refurbishment in a £1.26 million scheme by social housing group Incommunities, its spokesman said.