A rescue operation is under way to free a man who has become trapped at the top of a 290ft tall former mill chimney.
Emergency services were called to Dixons Chimney in Carlisle at about 02:20 GMT and a helicopter has been hovering near the top of the structure.
Footage from the scene appears to show a figure upside down with his legs in the air at the top of the chimney.
Firefighters have appealed for “anyone who has a cherry picker in excess of 90 metres within Cumbria” to contact them.
Roads around the prominent local landmark, which was built in 1836, have been closed.
A Cumbria Police spokesman said: “Emergency services have been working to safely resolve the situation at Dixons Chimney, including the use of a helicopter.
“However, rescue has not been possible due to the precarious position the man is in and the potential for backdraft to worsen the situation.
“Effort are ongoing to reach the man from below.”
A Cumbria Fire and Rescue Service spokesperson said: “This is a very complex and difficult process given the obvious dangers to the man and the extreme difficulty in gaining access to him in a way which will keep him and emergency services safe.
“I can assure the public that the emergency services are working tirelessly and effectively together to resolve this issues safely for all and that the protection of life is our first priority.”
Volunteers from the Penrith Mountain Rescue Team, the coastguard helicopter and a rope access crew from Lancashire Fire Service are also at the scene.