Firefighters were called to the blaze on Brooks Road in Chiswick last Friday (January 9) at 4.22pm.
The woman was rescued from the flat by firefighters and she was taken to hospital, where she died four days later on Tuesday (January 13).
Four other people were also rescued from neighbouring flats and they were taken to hospital as a precaution for smoke inhalation.
Dozens of other people were also evacuated, many of whom are elderly or vulnerable, and an immediate rest centre was set up for around 30 residents.
The fire took place in a first-floor flat and the communal corridor was also partially damaged.
According to the London Fire Brigade, firefighters arrived at the scene within three minutes as crews tackled the “challenging and well-developed” blaze.
At the time of publication, the cause of the fire remains under investigation.
However, the brigade has revealed at this stage that crews were alerted about the incident due to the automatic fire alarm sounding.
During this time, the first six calls were made to firefighters at 4.22pm.
The fire was eventually under control by 6.05pm.
London Fire Brigade Assistant Commissioner, Andy Pennick, said: “Our thoughts are with the woman’s family and friends as well as all those impacted by this sad incident.
“Both during and after the fire, local crews and officers have worked closely with our partners to ensure the other residents, many of whom are elderly or vulnerable, were well-supported.
“This included setting up an immediate rest centre for around 30 residents who were evacuated from the building.”
