A modern block of flats had to be evacuated in Newburn, Newcastle, after its foundations appeared to have been washed away.
The residents are among hundreds of people who spent the night in temporary accommodation after a second day of heavy rain brought flooding and travel chaos across Britain.
More than 300 properties have flooded across the country since Sunday, including in Morpeth, Durham, Chester-le-Street and Stockton on Tees, the Environment Agency said.
Forecasters warned that rivers could continue to overflow as downpours move towards north Wales and the north west of England.
However, torrential downpours that have flooded some parts of the UK with more than a month's rainfall in 24 hours should ease off throughout the day, weather experts said.