Homes were evacuated, power was cut and one woman needed hospital treatment after parts of Kent were hit by an earthquake.
The tremor - measuring about 4.3 on the Richter scale - struck just after 8.15am on Saturday in an area with a history of some of the worst British quakes.
The emergency services were inundated with calls as the ground shook and buildings were damaged, with cracks and toppling chimneys.
The Association of British Insurers (ABI) reassured householders that damage will be covered. The ABI's Nick Starling said: "These sudden, unexpected, and unwanted events are exactly what insurance is designed to cover."
Kent Fire and Rescue Service took more than a 100 emergency calls, ranging from issues concerning structural damage to gas smells. A spokesman said: "We have had calls from people saying their chimneys have fallen down, large cracks in people's houses."
The fire brigade investigated reports of someone trapped under a collapsed building but everyone was accounted for.
Electricity and gas supplies to houses in some parts of Kent were cut off. Scottish and Southern Energy, which supplies gas to the area, was investigating 300 "possible gas escapes" in the system.
EDF Energy, which supplies electricity to people in the Dover and Folkestone area, said several thousand customers lost power, but it was later restored.
Police said there were no reports of serious injuries. But South East Coast Ambulance Service said one woman in her 30s suffering from a minor head injury and neck pain was taken to hospital. It sent five ambulances and three officers to the Folkestone area.
The quake is the largest in Britain since an earthquake in Dudley in 2002. British Geological Survey seismologist Roger Musson said the tremor was around 4.3 on the Richter scale, with an epicentre 7.5 miles off the Dover coast. That meant it could be weakly perceptible as far as London.