The fire service has repeated safety warnings, after an inquest into the deaths of five people in a house fire in Sheffield concluded.

The tragedy on Wake Road, Sheffield killed three generations of the same family in April 2014.

Recording a verdict of accidental death, coroner Chris Dorries described the fire as “a tragedy of unimaginable proportion” and said the cause of the fire was “undetermined.”

Evidence was heard from forensic experts about electrical items which were found close to where the fire started. These included a mobile phone, phone charger and baby monitor charging cradle, but the coroner said none of these could be said to have caused the fire.

Smoke alarms were fitted in the property and operated that night, but the family initially believed it to be a false alarm.

The fire spread quickly and was described by firefighters as being particularly ferocious. This was aided by doors within the house remaining open, which helped the fire to spread, the inquest heard.

South Yorkshire Fire & Rescue’s head of community safety Kevin Ronan, said: “This was the most serious house fire in terms of loss of life that our crews have attended for many years. Our thoughts remain with the loved ones of those who died at what must be a time of enormous sorrow.

“Fires as serious as this are fortunately very rare, but when they do happen they affect our service personnel and the wider community very deeply.

“We’d remind people that whilst smoke alarms have the potential to save lives in house fires, they will only do so if people take the appropriate action when the alarm sounds- to get out, stay out and call 999.

“One of our main safety messages during talks and safety visits is to shut internal doors at night to stop the spread of a fire in the event one does occur. Unfortunately it does not appear that this happened at this incident, meaning the blaze spread incredibly quickly.”

Firefighters were praised during proceedings for their exceptional bravery, with Mr Dorries commending the first crew in attendance to the Chief Fire Officer for recognition.

Firefighters wearing breathing apparatus walked up a burning staircase in temperatures of more than 1000 degrees celcius to search for casualties, the inquest heard.

“We echo the words of the coroner who commended the actions of the first crew in attendance. The inquest was told that this was the most ferocious domestic fire firefighters with more than 25 years experience had ever attended, and it is right that their actions have been recognised”, said Kevin.

One of those who died, 53-year-old Shabina Begum, has also been nominated for a posthumous Royal Humane Society award in recognition of her bravery in attempting to rescue her grandchildren from the fire.

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