Stanmore firefighters were called to the scene of a huge blaze that left an 81-year-old woman dead.
Firefighters tackled the blaze, which took place on the first floor of a flat on Fulbeck Way on Sunday, October 21 at around 1am.
They rescued a man, woman and baby from inside the building.
The first floor partially collapsed due to the force of the explosion.
Firefighters used an aerial ladder platform and breathing apparatus to rescue the three others in the home, before being taken to hospital by London Ambulance Service crews.
The fire was under control by 3.33am.
The cause of the fire was initially believed to be a gas explosion.
However, it was later revealed that it was caused by petrol being poured throughout the property.
The woman who died in the fire has been identified as Ratna Alexander.
Her next of kin have been informed and a file has now been sent to the coroner, but the death is not being treated as suspicious.