Galleried chalk mine workings 2m to 4.5m high, 7m to 18m below ground level on four levels
Up to 28 houses, the school and adjacent roads could be affected by collapse.
The area affected covers 16,940m 2
An emergency plan should be put in place
Structural inspections of all properties should take place as soon as possible
More detailed assessment of the foundations of the school and two properties should take place