LONDON — British Prime Minister Theresa May’s office says that around 600 buildings in England have cladding similar to the type blamed for the quick spread of flames in the London high-rise disaster.

Councils in England made the estimate as authorities desperately try to get a grip on the scale of the issue facing local authorities following the blaze at Grenfell Tower that killed at least 79 people on June 14.

The aluminum composite material that clads the building has been singled out for scrutiny because the blaze engulfed the building in less than an hour. That has surprised fire officials, who have wondered aloud how a 24-story building could become an inferno so quickly.

Addressing Parliament on Thursday, May announced that the investigation into whether the tower met fire safety regulations will be published in the next 48 hours.

Emergency workers take part in a minute of silence on Monday to honor the lives of 79 people who died in the fire that engulfed Grenfell Tower last week. Associated Press/Kirsty Wigglesworth

Meanwhile, the local administrator in the west London community where the fire occurred has resigned after government officials criticized the chaotic response to the blaze.

Nicholas Holgate, chief executive of the Kensington and Chelsea council, had come under intense pressure. The first few days after the June 14 inferno were marked by chaos on the ground as local authorities struggled to deal with the scope of the aftermath.

Residents who survived the tower blaze lost everything, only to get little help or information on how they’d get back on their feet.

British Prime Minister Theresa May is expected to address the response to the fire in Parliament on Thursday.