London - Najiyah Hussain (3) was taken by ambulance to Newham General Hospital, east London, after suffering a fit and was given nitrous oxide instead of oxygen. A member of the medical team has been suspended pending a full investigation into her death, the Newham Healthcare NHS Trust has confirmed.
Her family is calling for hospitals across Britain to tighten their procedures so that someone else does not have to suffer another "tragic and sudden" death such as Najiyah's.
Najiyah's father, Mr Akmul Hussain, said from his home in Manor Park, east London: "She should have had the right treatment.
"She was a very lovely girl . . . a lovely girl and she had just started nursery.
"I feel terrible. How could they do that? It should not happen to anybody else."
Najiyah's funeral was held on Tuesday.