Police were called to Eastbourne Pier around 4.10pm to a man who had fallen onto the beach.
Ambulance was called and the man was being treated for a serious head injury and he was flown to hospital in a life threatening condition.
The Health and Safety Executive has been informed as the man was working on the pier.
More top news
Sunday evening's weather update for the east
Sunday evening's weather update for the west
A man has been taken to hospital with serious injuries after being beaten by a gang of 10 in the early hours of this morning.