Four fire engines and around 25 firefighters were called to a fire at a house in Grosvenor Road in Hounslow.
Part of the ground floor was damaged by fire.
Sadly, one man was pronounced dead at the scene. Ten other people left the property before the Brigade arrived. One woman was taken to hospital by London Ambulance Service.
The Brigade was called at 0244 and the fire was under control by 0427. Fire crews from Hounslow and Feltham Fire Stations attended the incident.
The cause of the fire is under investigation.