Part of the remains of Southampton's derelict historic Royal Pier have collapsed.
A 30m (98ft) section of the structure fell into Southampton Water shortly before 1000 BST.
The area is owned by Southampton City Council, The Crown Estate and Associated British Ports (ABP).
Last month, firms interested in developing the surrounding waterfront areas were invited to come forward with plans for its future.
The city council's cabinet approved the first steps towards redeveloping what it called "one of the city's most iconic landmarks" in March.
The Royal Pier was opened in 1833 and was used by steamers to France, the Channel Islands and the Isle of Wight.
A railway station on the pier took passengers to and from the rest of the country.
It was closed in 1982 after becoming unsafe and uneconomical to run, and was damaged by fires in 1987 and 1992.
Its impressive entrance building was recently reopened as a restaurant.
Hanif Brora, ABP's Head of Port Operations & Safety & Group Security Co-ordinator, said: "Since the fires of 1987 and 1992, and having been closed to the public for three decades, the Royal Pier has been structurally beyond repair.
"Today another section of the derelict structure has collapsed in on itself.
"No one was hurt and the incident occurred in an area not open to the public.
"This has not affected the safety of the harbour."