I remember hearing a caving crisis story but can't recall enough to find it again

Hello everyone, maybe you can help me out :)

I remember a story about an incident I think took place in the UK though I may be wrong on that.

The group entered the cave through one entrance and were going to exit through another, part of the route had an ascent where rope was needed. The weather happened to turn bad and the cave started flooding, which led to them having to battle rushing water on the ascent which obviously led to the risk of hypothermia.

I don't think anyone died. I vaguely recall one of the entrances being a locked hatch on private land. I think I saw a map of the cave, and the first leg of the cave was a relatively slow descent but the ascent being very steep. Like a V tilted to the left so the right arm points straight up.

I think the cave had a Welsh name, it wasn't porth yr ogof though.

I know this is all hella vague and probably stuff that happened in loads of expeditions but maybe someone has an idea what I think I remember, haha.