A couple today said they felt blessed to be alive after stepping on a manhole cover which promptly exploded.

Tessa Nelson, 44, and Graham Nelson, 59, of Wymer Street, Norwich, were walking to Tesco on Dereham Road yesterday afternoon when they were the victims of an unexpected electric fault.

Walking arm-in-arm with her husband, Mrs Nelson stepped on the manhole cover but the next moment found herself face down on the road and dazed.

The cover had exploded when she stepped on it, and a second explosion then occurred just seconds later – causing her husband to stumble.

It caused a large piece of concrete to fly in the air, narrowly missing Mrs Nelson upon landing, she said.

'It was unbelievable,' she said.

'It's not what you expect when you're just popping to Tesco to buy some bananas.

'Suddenly I was face down with shrapnel in my eyes and face. I couldn't open my eyes. It was a nightmare.'

Witnesses rushed to help the couple and Mrs Nelson was dragged to some grass nearby, where she was looked after until the emergency services arrived.

Fortunately for the shaken couple they only suffered cuts and grazes.

'The passers-by reacted brilliantly,' Mrs Nelson said.

'I was given tissues to clean my face, and everyone who looked after us were fantastic.'

The explosions, which occurred at 1.30pm, had been caused by an electrical fault which caused an explosion underground at a link junction between two electrical substations.

Emergency services, including fire crews from Earlham and Carrow fire stations, were closed the road and it was still closed late last evening.

UK Power Networks said it had to temporarily switch off electricity to 65 properties and the nearby Tesco Express.

Rob Burling, watch manager for Norfolk Fire and Rescue, said: 'There's a link junction between two substations which went out.

'There were sparks and an explosion which has lifted a manhole cover up. We shut the roads off and isolated the area.'

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