- Video report by ITV News Correspondent Paul Davies
Hundreds of residents will be evacuated from their high-rise flats after an investigation revealed they might not be safe.
The gas supply to 242 flats in four blocks on the Ledbury Estate in Peckham, south London, was cut off on Thursday.
Southwark Council said it knows the move is "inconvenient" for those living in the block, but it is "not willing to take any risks".
Concerns over the cracks in the building were raised by residents after the Grenfell fire tragedy which killed at least 80 people.
Structural engineers Arup were sent to investigate the cause of the cracks.
It was during this investigation that an historic issue was raised surrounding the gas supply to the four blocks on the estate - installed when they were built between 1968 and 1970.
A letter sent to residents states that in 1968 the similarly constructed Ronan Point in Newham, east London, partially collapsed after a gas explosion - prompting blocks around the UK to be made safe to carry a supply of fuel.
Stephanie Cryan, deputy leader and cabinet member for housing at Southwark Council, said despite records suggesting the blocks were strengthened following the Ronan Point incident, this may not have actually happened.
"Arup's structural investigations suggest this strengthening may not have occurred, and we have therefore turned off the gas, until further investigations can be done," she said.
"We are doing all we can to provide residents with alternatives while the gas is turned off, and are working up a plan to permanently replace the gas with electric ovens, boilers etc as part of the wider works, should that be necessary.
"We have also written to the Department of Communities and Local Government to inform them of this issue, as it may well have implications for other blocks around the country that were constructed in this way."
The council said it hoped residents could stay in their homes while work to fix the cracks was carried out.
But temporary accommodation will be found if the works are taking too long.
In the meantime, residents will be offered hotplates so they can prepare meals and the council is looking to install electric water heaters in every flat.
The authority said that those living in the block can access free shower facilities at any of Southwark's leisure centres.