A sinkhole has opened up in a St Albans cul-de-sac, forcing the evacuation of nearby houses.
Gas and electricity supplies in the area have been isolated since the hole, which has affected the gardens of three properties in Fontmell Close, grew rapidly overnight.
Hertfordshire's Fire and Rescue Service had first been made aware of a "small hole" on Wednesday, which was due to be filled in.
But by 1.30am this morning, the sinkhole had opened up substantially.
Julie Langford, who lives on the street, told Sky News she had been unable to take her car out of the driveway to head to work this morning.
She estimates there are 40 houses in the cul-de-sac - and all of the residents in the road have had their vehicles blocked in by the sinkhole.
Ms Langford has been warned it could take weeks - possibly months - before the road is fully repaired.
She added: "I can't walk to work - I have an hour's commute in the morning. The children can walk to school, but when you're a mum with four children it's not easy."
But she said there had been an excellent sense of community spirit in the street, and many of her neighbours were grateful no-one had been injured or worse.
According to Peter Hobbs, an engineering geologist with the British Geological Survey, sinkholes are caused by the dissolution of rock, such as chalk.
He added: "Alternatively, they can be caused by collapse into former mine workings (for flint within the chalk). Changes in the water table may affect the stability of underground cavities.
"Recently, the weather in this part of the country has been relatively dry and water tables may have lowered."
In August, a 40ft-deep hole in Manchester's Mancunian Way opened up - shutting a major route around the city centre.