Firefighters battled a blaze at a home for more than two hours last night.
Four fire engines and more than 20 firefighters from Stanmore, Wembley and Harrow worked from 10pm throughout the night to control the fire at a family home, in Woodcock Hill, Kenton.
Station commander John Doherty, from Harrow Fire Station, said: "It destroyed most of the ground floor, it was a really serious fire.
"Machines went out there from other stations to relieve the firefighters so we were on the scene for several hours."
The fire brigade investigation unit has launched an investigation, however it is believed the fire may have been caused by lit candles being left unattended.
No-one was in the house at the time of the fire, which happened on the night when many Hindus were celebrating Diwali, the festival of light.
The inferno started at the back of the house on the ground floor of the four-bedroom semi-detached property before spreading upstairs. The first floor roof extension of the house was also extensively damaged, but firefighters managed to stop the flames reaching the upper floors.
The fire brigade is warning people to be extra vigilant during Diwali and not leave any candles unattended and also advise people to observe safety rules when using fireworks.