Whipps Cross Hospital in east London has been forced to cancel planned surgery and outpatient appointments following flooding caused by heavy rain.
The maternity ward was also struck when ceiling panels collapsed, with maternity patients who require urgent treatment being asked to attend alternative hospitals where possible.
Although the unit is currently still open for walk-ins, maternity cases needing an ambulance could be sent to an alternative unit instead of Whipps Cross.
A hospital spokesperson said: “All elective appointments have been cancelled for today only while we work hard to clean up affected areas of the hospital. At present elective appointments later on in the week are unaffected but this may change”.
It seems that some appointments will be held virtually with affected patients to be contacted.
The hospital spokesperson said: “We are keeping the situation under constant review.
“We would like to thank patients for their understanding and remind the public to check our visiting arrangements before coming in. Further updates will be provided as the situation changes.”
Exceptionally heavy rainfall on 25 July caused parts of the hospital to flood, causing damage to the buildings and the electrical system, as well as a loss of power.
A major incident was declared, with some wards being evacuated and ambulances diverted to other hospitals.
A spokesperson for Barts Health NHS Trust urged people to check visiting arrangements before attending the hospital.
They said: “We are working closely with other hospitals across the Barts Health group to maintain patient care and asking the public to check the latest visiting arrangements for each hospital on our website before coming to any site.”
The two other hospitals in the same NHS Trust - Newham and St Bartholomew’s - suffered some flooding on Sunday but remain fully operational.
The news comes as the Met Office has issued warnings for heavy rain in England and Scotland over the next few days.