A family have been told not to sleep in their home after a 30ft-deep sinkhole opened up in the driveway and swallowed their car.
Firefighters were called to the property in Main Road, Walter's Ash, High Wycombe, Buckinghamshire, at 8.32am yesterday, when they found the 15ft-wide hole.
Phil Conran, who lives in the house with his wife Liz, told BBC News he initially thought the Volkswagen Lupo, which belongs to his 19-year-old stepdaughter Zoe Smith, might have been stolen until he realised it had disappeared into the ground.
"The initial shock was very quickly overtaken by relief because, had she been going out to the car when this happened - had she been in the car just pulling away when this happened - then obviously if you look down the hole you can see the car is completely full of earth," he said.
"It would have been absolutely horrendous. So frankly that overtook any thoughts of shock, really."
Mr Conran said the family have been told not to sleep in the house amid fears of further subsidence.
When the hole first appeared, they did not know what to do, so called the police, who initially told them to contact insurers and the council, but then several officers and a fire engine arrived, he told the BBC.
"They obviously were a bit concerned about potential for further subsidence. They were quite keen for us to get out of the house, but I think people then quickly accepted that actually this was a fairly isolated problem," he said.
"We've still been advised we shouldn't be sleeping here, but we can use it during the day."
He went on: "We had a guy from building control from Wycombe District Council. His feeling is that it's a combination of factors and yes, the wet weather is probably the final straw."
Mr Conran said the area was known for chalk mining which happened "probably 150 years ago" and there were a series of underground tunnels.
"All the houses here are built on concrete rafts, but that doesn't mean that things like drives can't disappear," he added.
His wife Liz added that she was "very worried" about their family home.
Describing the moment her daughter saw the sinkhole, Ms Conran told BBC News: "She was in absolute hysterics. It didn't dawn on us what had happened until after about an hour."
Ms Smith told BBC News that she screamed as she looked out of the house window, thinking her car had been stolen.
"There was just a crater, at which point I screamed the house down," she said.
"I'm quite lucky I've got parents who are good in a crisis and said it's OK, it's just a car and you weren't in it."
Explaining how the sinkhole might have formed, Paul Beetham, a lecturer in civil engineering at Nottingham Trent University, said: "High Wycombe is a chalk area, and chalk has properties quite different to other types of rock. Areas underlain by chalk may contain natural voids or caves, which formed over many thousands of years as groundwater passed through and dissolved the chalk.
"High Wycombe is also an area that has been mined historically for chalk and, occasionally, mining areas can have access shafts which were not capped off correctly, leading to loose material overlaying these voids.
"While such cavities may remain intact below ground for hundreds of years, very rarely the sudden collapse of the material may occur, perhaps when disturbed by extreme rainfall or a recent change in land use."
A Buckinghamshire Fire and Rescue Service spokesman said: "Firefighters were called to a sinkhole (30ft deep, 15ft diameter) which swallowed a parked car in the driveway of a house in Main Road, Walter's Ash.
"Firefighters placed a cordon around it and gave safety advice.
"The incident was handed over to building control at Wycombe District Council. Firefighters were at the scene for about an hour."