Part of Lake District crag Castle Rock collapses
A slab of rock the size of a bungalow and thought to weigh 1,000 tonnes has fallen from one of the Lake District's best known crags, its owners have said.
A crack was first spotted at the top of Castle Rock, near Keswick, in 2010, prompting warnings to climbers that it showed signs of "major instability".
Staff from United Utilities, which owns the land on which the 1,112ft (339m) crag sits, witnessed the collapse.
No-one was reported injured in the incident.
The imposing crag, whose full name is Castle Rock of Triermain, has been popular with climbers in the Lake District for hundreds of years.
Warning signs were put in place when it was discovered the crack had forced a section to move by 3in (7cm).
Earthquakes in Coniston, Dumfries and Morecambe Bay in May 2015 are thought to have had an impact.
United Utilities said staff working at a nearby forestry office observed the collapse.
A spokesman said: "A rock fall which has threatened Castle Rock finally happened at 2pm today.
"Our staff heard a loud rumbling noise and observed a large plume of dust, and on investigation discovered a section of rock had fallen away.
"Since the crack was discovered in 2010, it has been widening and it was only a matter of time before the fall occurred.
"The noise when it happened was quite considerable, but the section which has come away shattered on impact on the scree below the crag.
"It never reached the forest boundary where trees form a natural barrier to falling rocks from the crag."
Alerts have been sent to climbing organisations and Newcastle and Durham universities who have been monitoring the crack.
The spokesman said warning signs would remain in place, and urged climbers to keep away from the area until a full inspection was carried out.