This story popped up on PBS radio this morning, but it is not new.
https://www.nytimes.com/2020/09/07/world/europe/london-bridges.html
(Apologies for the paywall, but the photos are good). This one from the Guardian has no paywall.:
I am sorry to see this---it is such a beautiful bridge. But the cast iron is difficult or impossible to repair.
Apparently the danger of collapse is great enough that even boats are banned from passing underneath it, along with pedestrians on the riverside path.