An inquiry has found that an electrical substation fire that shut down Heathrow Airport in March was caused by a preventable technical fault identified almost seven years earlier.

A report into a fire that resulted in Heathrow Airport shutting down for nearly a day has been released - what are the key findings?

Energy watchdog Ofgem has now launched an investigation, after a report revealed the 'catastrophic failure' that caused the fire in March. | ITV National News