Gavin Grey: UK correspondent on the investigations into the Heathrow shutdown - Heather du Plessis-Allan Drive

New reports have revealed power was available to keep London's Heathrow Airport open throughout the recent shutdown.

Two other substations remained operational and capable of powering the airport - but the shutdown was called due to the time it took to switch from the damaged substation to the other two.

UK correspondent Gavin Grey says this update came as a shock to many people who got stranded.

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