The Grenfell Tower fire in London started in a fridge freezer, the police revealed on Friday, reported The Independent. The police said that both the insulation and tiles at the building failed safety tests and they are considering manslaughter charges. At least 79 people were killed after the blaze destroyed 151 homes in the Kensington tower block.

“Preliminary tests on the insulation samples collected from Grenfell Tower showed that they combusted soon after the test started,” Detective Superintendent Fiona McCormack from the Metropolitan Police said. “The initial tests on the cladding tiles also failed the safety tests.” McCormack, however, added the fire was not started deliberately.

Rydon was the company responsible for cladding and retrofitting refurbishments at Grenfell Tower. Earlier, an investigation of the supply chain had revealed that out of the two available options, a cheaper, more flammable material was used in the cladding to cover the Grenfell Tower.

The fridge freezer that started the fire was a Hotpoint FF175BP model. The police said the manufacturers, as well as the Department of Business, Energy and Industrial Policy had been informed. The police said further tests were being conducted on the appliance and the fridge freezer had never been subject to a product recall.

Manslaughter charges are among a string of offences being considered by the police as part of the investigation, McCormack said. “We are looking at every criminal offence from manslaughter onwards, we are looking at every health and safety and fire safety offence and we are reviewing every company at the moment involved in the building and refurbishment of Grenfell Tower,” she said.

McCormack said the police had been in the tower “from top to bottom”. She said that a lift would be installed to the outside of the building next week. Some 250 specialist investigators are working on the case to find out what happened.