Investigations are continuing today after a gaping 20ft hole forced a hotel to be cordoned off and the evacuation of Norwich's Plantation Garden, which will remain closed over the weekend.
The hole, believed to be caused by the collapse of an old mining tunnel beneath the ground, opened up at the side of the Plantation Hotel, in Earlham Road, yesterday.
Fears for the structure of the hotel led to a cordon being put up around it. A large crack was visible near the main entrance and a nearby window was pushed out of alignment.
Surveyors from CNC Building Control found the cracks extended from the Grade II-listed hotel across the car park and into a medieval wall of the Plantation Garden next door.
That led to a decision to evacuate the gardens just before 2pm yesterday. Police were called to the scene and five people in the gardens, including a family of four, had to leave.
The gardens were closed, with police tape over the gates, and will remain so until at least Monday.
Roger Connah, chairman of the Plantation Garden Preservation Trust, said he had received a call from Tony Burlingham, who owns the hotel, part of the MJB string of properties, at 2pm.
Mr Connah said: 'There is an issue of subsidence in the corner of the hotel with the cracks leading to a major wall in the Plantation Garden.
'So, the decision was quickly and sensibly taken to close the garden and they have had to shut the hotel. I don't know how long that will be for, whether it is for a day or for a month. We're waiting to see.
'But we've decided to keep the gardens closed until Monday, when we will decide what to do based on advice.'
Mr Connah said the Plantation Garden was itself a chalk quarry, with mining tunnels leading off it, which was transformed into a garden in the 19th century.
He said: 'We had our own sinkhole about five years ago when a water pipe burst, but we know there are lots of tunnels in the area which used to be used for flint mining.'
Anglian Water attended, but confirmed it was not an issue with their equipment. Mr Burlingham was not available last night.
The location is just a stone's throw away from where a double decker bus fell into a sinkhole in Earlham Road in 1988, making headlines around the world.
As the driver attempted to pull away, a large section of the road surface collapsed beneath the rear wheels.
An old chalk mine, dating from the 11th century, had given way, but the passengers managed to scramble clear.
• Were you affected by the subsidence? Email newsdesk@archant.co.uk
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