WELLINGTON, N.Z. (AP) - New Zealand's largest telecommunications provider was checking Tuesday whether rats gnawing a cable were partly to blame for an outage that disrupted mobile phone and Internet services and shut down the country's Stock Exchange on Monday.
Telecom Corp. spokesman John Goulter said the company "could not rule out the possibility" that rodents got into its ducts north of the capital, Wellington, and chewed through the fibre-optic cable.

An investigation of the cause was in progress. A second cable had been cut by a post-hole digger on the west coast of North Island.

Communications Minister David Cunliffe played down the problem, saying, "I think getting two accidents of this type at the same time is a freak occurrence."

The Center for Advanced Engineering, an engineering and technology think tank, said the failure suggested that New Zealand's infrastructure may be too vulnerable to "network failure."

Modern infrastructure systems have become "highly sophisticated networks" that could leave New Zealand vulnerable to "cascade failure," in which disruption of one network had a domino effect, said center head George Hooper.

Hooper said New Zealand needs to develop systems that can be protected from the economic and social upheaval of widespread failures.