A Teesside angler suffered serious injuries after falling 30ft through a jetty and down a disused pumping shaft.
It is understood the jetty, on Beach Road in Skinningrove, near Saltburn, gave way late on Friday night.
Coastguard, fire and ambulance crews were called to the scene and were all involved in the rescue operation.
The man, who has not been named, was taken to Middlesbrough's James Cook University Hospital with head, leg and spinal injuries.
No-one else was injured.
A coastguard spokesman said: "At first it was thought he could have fallen into the water.
"We then found he had fallen into a pipe that was part of an old cooling water system for the steel works."