Britain's National Health Service (NHS) has drawn up emergency plans for four East Anglian region hospitals at risk of structural collapse.
Under the "mass casualty plan", patients would be evacuated and ambulances re-routed ambulances to other sites, while non-urgent cases would be discharged to clear the decks for the influx.
The Operation Rapture plan would be set in motion "significant hospital structural failure" at the Hinchingbrooke Hospital in Cambridgeshire, West Suffolk hospital and the Queen Elizabeth and James Paget hospitals in Norfolk.
All four hospitals have serious structural issues due to the use of reinforced autoclaved aerated concrete (RAAC) planks in their construction in the 1970s and 80s. The planks are much weaker than typical concrete building materials and experts say they should be replaced after around 30 years — 10 or 20 years less than the age of the buildings.
In 2020, NHS East of England conducted 'Exercise Hodges', which simulated the collapse of part of one hospital.
Meanwhile the West Suffolk NHS Foundation Trust, which runs the hospital in Bury St Edmunds, commissioned a report into its potential liability for corporate manslaughter in the event of the roof falling in. That found that a collapse was "almost certain" and could be "catastrophic".
The trust's interim chief executive Craig Black told the BBC it was "really sad" that a staff member had leaked the documents.
"We have weekly briefings on the situation around RAAC," Black said. "We have posters up around the hospital; we talk to staff continuously".
The report was leaked by a whistle-blower concerned that patients were being kept in the dark, the Mail Online reported. The alarm was first raised after the roof of a school in Essex, made from the same RAAC material, collapses in 2018.
Metal beams have been placed under the planks at some hospitals for extra support — more than 200 at the Queen Elizabeth Hospital in King's Lynn alone. Hinchingbrooke Hospital has banned patients weighing over 19 stone (120 kg) from being treated on certain wards.
The government ringfence £110 million earlier this year for repairs to the four East Anglian hospitals, along with Airedale in West Yorkshire, Leighton in Cheshire and Frimley Park in Surrey which were built with the same material.
"Trusts in the East of England work in line with specialist industry advice and have been given more than £67m to help them manage their estates programme," an NHS East of England spokesman said.
"Trusts have maintained safe services for patients, who should access hospital care as they normally would, and also introduced a number of measures including improved surveillance and use of specialist equipment to help identify and fix any issues immediately."