A World War Two Bletchley Park codebreaker is one of 19 people being forced out of a financially-troubled care home with just 18 days' notice.
June Wrobel, 93, who has dementia, must leave Weald Hall in Wadhurst, East Sussex, by the end of the month.
The most recently published accounts for the home show it owed more than £1m to creditors, of which £350,000 had been due before 31 March this year.
The home's owner, Alice Bock, declined to comment to the BBC.
Mrs Wrobel's accommodation was costing £1,100 per week. In a letter on 12 August Ms Bock told her family the home would close on 31 August.
She said she had "struggled to turn around a home that had been in previous financial difficulties".
Problems with staff recruitment and resident numbers, she said, made its operation "untenable", and the short notice period was due to depleted staff numbers making the environment "unsafe".
'Shaking a lot'
A second letter from the home seen by the BBC warned families that they could face legal action by speaking to journalists.
Mrs Wrobel's son, Michael, said she was "very withdrawn, very agitated, shaking a lot" and kept saying, "'I'm worried, what's going to happen to me?"
Her daughter-in-law, Jutta, said: "Private care homes, where residents pay significant amounts of money, are perhaps not as regulated as state-funded care homes.
"A light needs to be shone in the corners there, to see what is the comeback, where is the duty of care, and how protected are people?"
The family has found Mrs Wrobel a new home, but it is substantially smaller so she is unable to take many of her belongings with her.
An planning application from Weald Hall Care Home has been sent to Wealden District Council, requesting permission to knock down the staff accommodation and garage at the back of the home and put in four homes.
An East Sussex County Council spokesman said: "We understand this is a distressing time for residents and their families, and we are doing everything we can to support them and to minimise the disruption following the provider's decision to close the service."
The home's most recent Care Quality Commission (CQC) inspection one year ago found that it "required improvement".