A coroner said the delay by the ambulance service in giving care to Norfolk baby Bella Hellings was "wholly indefensible".
William Armstrong concluded the three-month-old died as a result of congenital heart disease after delays in medical assistance reduced her chances of survival.
He said: "We are told that at the time the ambulance service was experiencing significant demand and there were apparently insufficient resources to meet that demand.
"Twenty-six minutes is a very, very long period of time indeed.
"The delay in giving Bella the care that she needed was wholly indefensible. There was a catalogue of catastrophes and a chaotic response."
More top news
Mild, windy and mainly dry.
It's not Father Christmas' usual mode of transport but these young patients didn't seem to notice.
Mild, generally dry and breezy.