Several homes in Britain were cut off from roads when a large sinkhole opened in Hertfordshire the very night before it was to be filled in.
"Work was scheduled to fill it in this morning," a Hertfordshire County Council spokesman told the BBC. "Following our inspection, there was no reason to suspect that the hole would collapse."
The sinkhole opened up across the driveway and front yard of a home in a cul-de-sac, spreading into the street to create a 66-foot-wide, 33-foot-deep hole in the town of St. Albans in Hertfordshire, northwest of London.
The county council of Hertfordshire knew about the hole because a Royal Mail postman had hurt himself earlier that week when a drain cover gave way. The council said there was no idea then of the small hole opening up into a huge sinkhole because in Hertfordshire such holes often crop up "for historic reasons," Richard Thake, Cabinet Member for Community Safety, told local radio BOBfm Home Counties.
Sudden patterns of sinkholes can be the result of climate change – wetter winters alternating with drier summers can make the ground unstable – and soft rock that dissolves quickly underfoot. Buildings can make them more likely, as water running off a roof can make the ground soggy, according to The Mirror. In Feb. 2014, for example, eight new sinkholes appeared in England, according to Esri, a geographic analysis company.
The hole has cut five homes off from the main road, and the residents have evacuated to a community center. It may take weeks or even months to repair the road. This had Julie Langford, who couldn't get her car out of the driveway to drive to work Thursday, concerned.
"I can't walk to work - I have an hour's commute in the morning," she told Sky News. "The children can walk to school, but when you're a mum with four children it's not easy."
Such sinkholes can certainly be inconvenient, but they are not altogether uncommon. Florida experiences sinkholes regularly, with more than 300 in the last 5 years, according to The Christian Science Monitor.
A sinkhole even opened up this summer in Brooklyn, N.Y., The Christian Science Monitor reported in August, although it resulted from leaky pipes rather than naturally eroding rock.
In the US, sinkholes are usually associated with limestone that is slowly eroded away by acidic water. In England the cause is more likely to be chalk, but the process is similar.
"Changes in the water table may affect the stability of underground cavities," Peter Hobbs of the British Geological Survey told Sky News. "Recently, the weather in this part of the country has been relatively dry, and water tables may have lowered."