A Filipino nursing assistant – John Alagos, 24, became ill and died on Friday after working at Watford General Hospital in Hertfordshire.
His mother Gina Gustilo told the BBC the family were waiting to hear whether he had tested positive for Covid-19.
The hospital closed to new patients on Saturday due to problems with its oxygen equipment, but has now reopened. It said it ensured staff had the right level of protection when working.
Tracey Carter, chief nurse at the hospital, said: “John was very popular and will be missed greatly by his colleagues.”
Mrs Gustilo, who is an NHS mental health nurse and lived with her son, said she had shown no symptoms of the virus but was self-isolating at home.
In a statement issued after Mr Alagos’ death, Ms Carter added: “Our staff are fully briefed on the symptoms of Covid-19 and we would never expect anyone to remain at work if they were showing these symptoms or indeed were unwell in any way.
“We have always kept our staff updated on the latest PPE guidance to make sure they have the right level of protection for where they are working.”
The hospital said the decision on Saturday to declare a critical incident was taken as a “result of a technical issue with our hospital’s oxygen equipment”.
This article originally appeared on: https://www.bbc.com/news/uk-england-beds-bucks-herts-52172288