Problem with Debenhams is that they simply couldn’t service the debts they have. Its not that someone has called their debt, but just that regular payments cannot be met when you have forced closures of shops, and while the government has been paying staff wages, that does nothing to help the large number of other ongoing costs like rent, debt repayments, payments to suppliers for goods delivered months ago, business rates, pension contributions, etc.
All very predictable. The UK economy is incredibly reliant on consumer spending, and if you close all the shops and tell people to stay at home that consumer spending grinds to a halt. As much as Professor Whitty and Co are health experts, they are not economic experts and the sidelining of the economic impact to preserve public health has been a major failing of the government's response.
The worst is yet to come - even the government themselves are predicting an 11% contraction in GDP which would be shocking over an extended period of time, but for that to happen within 18 months is almost unprecedented and all self inflected. It's a compete disgrace, especially so from a Conservative government which has traditionally always been very pro-business and pro the economy.
Quite likely that the worst is still to come