Neighbours on an estate rocked by the dramatic opening of a sinkhole are gearing up to celebrate the official reopening of their road – more than a year after the chasm first appeared.

Families living on Fontmell Close and Bridle Close were awoken in the early hours of Thursday October 1 last year by the sounds of emergency services working right on their doorsteps.

READ MORE: Sinkhole families still waiting to return home

However one man took it upon himself to warn his sleeping neighbours of the threat before the fire service could arrive, skirting the gaping hole and risking injury, or worse, in a remarkable act of neighbourly love.

His heroism was made all the more outstanding by the fact he had his heavily pregnant wife waiting for him back home.

“He sprinted from round the other side of the hole to bash on our door, and our elderly neighbour’s door, to warn us of the impending danger,” said Fontmell Close resident David Walker.

“Soon after he warned us, the police, fire brigade and gas board turned up to turn off the gas in case there was a fire.

“We were told to stay inside until we were taken to a Red Cross-run evacuation centre at a local leisure centre. When we got there, my wife was still so shocked she gave our address from ten years ago.”

The cavity was quickly filled with lorry loads of foamed concrete but the discovery that much of the estate was built on the site of an old chalk mine meant extensive surveys had to be completed before the area could be declared safe.

Mr Walker and his wife Virginia were unable to return home for eight weeks, along with two other immediate neighbours.

However four households remained evacuated for a much longer period, and have still not been given the all-clear to return, although it is hoped they will be able to move back home the next couple of weeks.

One of those homes belongs to the unidentified hero, his wife, and their baby.

The road will be officially reopened on December 3 by St Albans mayor Frances Leonard, who will cut the ribbon to spark celebrations from neighbours whose lives were turned upside down on that night in October.

“Everyone is happy to collectively celebrate this reopening. Not a single brick on any of the houses was disturbed. Once we felt safe we just got on with our lives to be honest,” added Mr Walker.