THOUSANDS of families were left without gas for up to a week because a lump of concrete fell on to a supply pipe, The Northern Echo can reveal.

About 6,500 homes in the Crook area of County Durham had their gas supply cut off in February after a major leak near Spennymoor.

Yesterday, a spokesman for gas distributor Northern Gas Network (NGN) said the company was reviewing a report which said a falling lump of concrete, dislodged during maintenance, fractured the mains pipe.

Residents caught up in the crisis expressed surprise at the finding.

Keith Johnson and his family, who live in Beechburn Drive, Crook, were left without gas for five days.

"Something like that should never happen. They should be more careful about it. My family were left in the cold for five days," Mr Johnson said.

Kath Oldfield manages Windsor Court, a sheltered housing estate in Bishop Auckland, where the supply of 24 elderly people was cut off for six days.

She said: "The residents had no heating or hot water, and some are in their 80s and 90s.

"They're vulnerable and were very distraught. It was shocking. I hope they get their priorities right in future."

The GMB trade union, which represents many of the North-East's gas workers, said the incident should be a "wake-up call".

Gary Smith, a GMB national officer, said: "The apparent increased use of contractors by United Utilities and Northern Gas Network could further undermine safety and good working practice.

"This incident is a wake-up call, and the GMB hopes they will reverse any attempt to increase the use of contracted labour and start negotiating with us over increasing direct labour resources."

John O'Grady, the director of communications for NGN, said: "Contractors have been used in the gas industry for generations successfully, working alongside direct labour employees delivering the full range of operational services.

"NGN is reviewing the investigation report with its operator, United Utilities, and with other contracting partners.

"NGN has full confidence in all its operating partners.

"Safety is always our most important priority in everything we do."

The gas crisis is expected to cost £1.5m, of which about £457,000 will be compensation payments to businesses, organisations and individuals.