Part of Streatham swimming pool has shut because the deteriorating leisure centre is falling apart.
The shallow end of the pool in Streatham High Road has been closed since Monday morning, when it was noticed a gap had appeared between ornate plaster work on the wall near the ceiling.
It was feared large parts of crumbling plasterwork could fall into the pool.
Swimming lessons have been cancelled at the pool until further notice.
Early today scaffolding was put up in the balcony of the 80-year-old building so that structural engineers could assess the situation.
The problem has raised further concerns about the future of Streatham's leisure centre.
The council has promised to maintain the leisure centre and fund it to remain open until building works start on the long-anticipated Streatham Hub development - being built with Tesco - which includes a brand new state-of-the-art leisure centre and ice rink.
But delays in the delivery of the development, already three years behind schedule, has meant the leisure centre has deteriorated further.
A council report published in August said : “The leisure centre was well beyond its life expectancy and is in a very poor state of repair” and its services were “severely compromised”.
Tim Barnsley, a regular user of the pool who has been campaigning for improvements at the centre, said he had no doubt the council intended to keep the leisure centre open until work on the Hub started.
He added: "But given the current state of the building, it is going to be increasingly difficult for Lambeth to fulfill that commitment as a deal has still not been done with Tesco."
He said: "Users are now waiting anxiously to see just how bad the current problems turn out to be."
A council spokesman said: “We have identified a problem with part of the ceiling at one end of the pool, so we have temporarily closed the shallow end while we make repairs.
"We are working to fix the problem as quickly as possible but are sorry for any inconvenience this causes and ask people to bear with us.
“Streatham L eisure Centre is showing its age and no longer provides the quality of facilities that local people deserve, and that’s why we are committed to providing brand new, state-of-the-art leisure facilities including a swimming pool as part of the Streatham Hub Development, as well as a new leisure centre in Clapham.”
Revised plans for the delivery of the Streatham Hub development are being drawn up by Tesco and Lambeth Council and will be made public by the end of the year.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here