LONDON -- London's fire commissioner says there have been 6 fatalities at an apartment building in West London. Fire crews are responding to the fire early Wednesday morning that swept through an apartment building in London, England.

According to the London Fire Brigade, at least 200 crew members were battling the fire at the Grenfell Tower in west London, which burned from the second to the top floor of the 27-story building. The building is about a mile northwest of Kensington Palace.

Striking images show progression of London apartment fire

At least 40 fire engines were sent to the tower, and the BBC reports there are fears that the building might collapse.

The London Metropolitan Police are evacuated residents away from the 120-unit building and some people are being treated for a "range of injuries."

London's Ambulance Service says 74 people are being treated following a massive apartment blaze in west London.

Paul Woodrow, the head of operations, says that 20 of those patients are in critical condition. He said that the patients were being treated for a range of injuries and smoke inhalation.

Police said that six people have died in the blaze, which broke out after midnight Wednesday at Grenfell Tower, an apartment block housing 120 homes, according to the Associated Press.

The service says a major incident has been declared.

Stuart Crichton, the Ambulance Service's assistant director of operations, says 100 medics are on the scene, together with ambulance crews and advanced trauma teams.

Police are urging people to avoid the area.

Ousama Itani, who lives in the area, told NBC News she woke up from sleeping and saw the flames and heard screams for help.

"We wake up early sometimes anyway in the night, and one of my relatives saw the flames from the window and heard the people screaming," Itani said. "It just started to burn across from one side to the other, and we saw apartment after apartment getting lit up in flames."

People passing by the fire posted incredible pictures and video to social media.

The Associated Press contributed to this report.