Code: Telstra phone and internet services lost after cable cut in Sydney AAP September 16, 2009 12:30pm THOUSANDS of businesses and homes in Sydney's CBD could be without phone, internet and mobile phone coverage for up to a week after a contractor accidentally severed crucial cables. Contractors working for Energy Australia cut through a bundle of 10,000 Telstra copper wires and some multiple-fibre optical cables near the corner of York and Erskine streets about 9.30pm (AEST) yesterday. The contractors have told Energy Australia they used "Dial Before You Dig" plans before digging, but an audit of the contractors, work equipment and procedures is being carried out. Telstra spokesman Craig Middleton said thousands of customers across the northeast of the CBD would be without mobile, fixed and wireless services for about a week. "There will be many thousands, the exact number we don't know because we're still plotting where this cable serves in the city," Mr Middleton said. Related Coverage "We are digging out the damaged section of cable that was damaged by a jackhammer." He said 10 major copper and optical fibre cables had been damaged. "It's gone through about 400mm of solid concrete at the moment to get to the damaged section and then we can restore the cable by pulling a new section through from Kent Street." Mr Middleton said Telstra would look at helping individual customers with line redirection where possible. An Energy Australia spokesman said the contractors responsible had been digging trial holes as part of cable upgrade works in the CBD associated with the new city north electricity substation. "We are concerned about the incident and are conducting a thorough investigation into the contractors' activities," the spokesman said. "We want to determine what happened, how it happened and whether the contractors did everything by the book." The company would take action if the correct steps had not been followed, he said. "Energy Australia apologises on behalf of the contractor because we understand this has caused considerable inconvenience to Telstra customers." Telstra and Energy Australia have launched an investigation into the incident. Affected customers should contact Telstra on 13 22 03.