Alberta Health Services says a communications mix-up is the reason why it took an ambulance 30 minutes to respond after dogs attacked an 86-year-old woman in Calgary.
It says the call for help was initially triaged as non-life-threatening.
Police later told emergency medical services that the woman's injuries were serious and she died.
Police say the three dogs, which were seized by the city, are believed to be a North American pit bull-terrier mix, a North American Staffordshire mix and an American pit bull.