Nearly 200 firefighters and 40 fire engines tackled the huge blaze that engulfed London's Grenfell Tower on the Lancaster West Estate in Latimer Road on the night of 14 June. The building is in a built-up area of West London.
The Metropolitan Police have confirmed six deaths related to the fire. They expect the number to rise.
London Fire Brigade Commissioner Dany Cotton confirmed there were numerous fatalities but could not confirm the number due to the complexity of accessing the still smouldering building. Cotton described the fire as an unprecedented incident, the likes of which she's never experienced in her 29 years of fighting fires.
Dramatic footage showed the entire building on fire, with flames leaping out of the windows. Firefighters' efforts seemed to have little impact on the huge blaze. Thick smoke is seen billowing from the burning structure and drifting across the London skyline.
The fire, the cause of which is unknown, was first reported at around 1.16am BST on Wednesday (14 June). By 6.15am, the fire seems to have burnt through most of the apartment block, but flames could still be seen.
Firefighters were reported to have accessed the building and evacuated most of the residents. The building is now a ruin, with fears it may collapse as debris is seen falling from it. Police are moving onlookers away from the site.
The Metropolitan Police said they evacuated a number of residents from the apartment building, and "a number of people" have been treated for injuries without giving any exact details. The London Ambulance Service said it has taken 50 people to five hospitals in the city.
Eye witnesses were reported as saying that they heard people screaming for help from the tower. Some unconfirmed reports also stated that people were seen jumping from the burning building.
"I was in my kitchen and heard smoke alarms. I could see the whole right side of the building was on fire," Reo, an eyewitness, told Sky News.
Another witness, Celeste Thomas, who lives across the road from the tower, said residents and families were "trying to find each other" following the evacuation. "Police have moved everyone back out of direct sight but I can hear cracking and debris falling," she added.
Sky News producer Dan Cairns, who was at the scene, said that fire officials have told residents in the area to advise people trapped in the building to self-evacuate. "They are being told to put a cloth over their mouths and try to get out by themselves."
"Firefighters wearing breathing apparatus are working extremely hard in very difficult conditions to tackle this fire," London Fire Brigade assistant commissioner Dan Daly told reporters on Wednesday morning.
"This is a large and very serious incident and we have deployed numerous resources and specialist appliances."
London mayor Sadiq Khan has tweeted about the incident and has urged people to follow London Fire Brigade on Twitter for more updates. #Grenfell Tower and # London fire are currently trending on Twitter.
According to the Studio E architects, the original builders of Grenfell Tower, the building was constructed in the early 1970s as a residential regeneration project.
Information available on the Royal Borough of Kensington and Chelsea's website states that the 24-storey tower has 120 flats. It underwent a £10m refurbishment which was completed in 2016.