A 66ft (20m) sinkhole has opened up on a residential street in St Albans, forcing the evacuation of families in the area.
The giant hole spreads across the driveway and front garden of a property on Fontmell Close and is 33ft (10m) deep.
Hertfordshire Fire and Rescue Service said at least 10 people have been evacuated to Batchwood Leisure Centre.
More than 50 properties are without gas and electricity, according to a fire service spokeswoman.
The fire service said it was already aware of a small hole on Wednesday and it was due to be filled in, but it then received a call at 1.30am to say it had "opened up substantially" overnight.