Santa Clara County officials have declared a local emergency after they said someone intentionally cut an underground fiber optic cable in south San Jose, causing a widespread phone service outage in southern Santa Clara and Santa Cruz counties today that included disruption to 911 emergency phone service.

John Britton, a spokesman for AT&T, said it appears somebody opened a manhole in South San Jose, climbed down eight to 10 feet and cut four or five fiber-optic cables.Britton also said there was a report of underground cables being cut in San Carlos.

AT&T is offering a $100,000 reward for information leading to the arrest and conviction of whoever is responsible for the sabotage, Britton said.

The outage initially affected some cell phones, Internet access and about 52,200 Verizon household land lines in Morgan Hill, Gilroy and Santa Cruz County, according to the Santa Clara County Office of Emergency Services. The cell phone networks affected are Verizon, Nextel, Sprint and some AT&T.

Verizon is the sole provider of land lines in the South County area.

“We’ve never to this extent in recent history had this kind of phone outage,” said Gilroy police Sgt. Jim Gillio.

ATMs in South Santa Clara County were not working.

Saint Louise Regional Hospital in Gilroy cancelled all elective surgeries in response to the emergency, according to county officials.

“It’s kind of like an earthquake” said Jack Ahlin, a driver with T. Marx Towing who was standing outside the Gilroy police department.

Service is also affected in South San Jose around Monterey Road and Bailey Avenue.

Crews are repairing cut wires located underground on Monterey Road just north of the Blossom Hill Road exit in South San Jose. As of 2 p.m. one of the cables had been repaired and some service had been restored, Britton said. Full service is not expected to be restored until about midnight.

San Jose police spokesman Sgt. Ronnie Lopez said the manhole covers are heavy and would take quite an effort to lift, perhaps even requiring a tool.

AT&T’s contract with the Communication Workers of America expired at 11:59 p.m. Saturday, but Britton said “we have a really good relationship with the union” and that negotiations continue between the two sides.

Asked if the potential sabotage had anything to with the strike-threatened contract negotiations between AT&T and the Communication Workers of America, union national spokeswoman Candice Johnson replied: “Absolutely not. Our members are not involved in this.”

Johnson said that CWA would cooperate with the investigation. Any implication that a disgruntled worker cut the wires was false, she said.

“That would be counterproductive, ” Johnson said “We are on the job. So it doesn’t make any sense. Our goal is to get a quality, fair contract and that us our focus right now.”

Johnson said she did not know if police had contacted the local union.

Meanwhile the disruption continues for thousands of residents.

The Santa Clara County Emergency Operations Center has been activated; the Santa Clara County Fire Department has moved more firefighters to south county fire stations; the county sheriff has increasing staffing and patrols; and additional ambulances have been positioned in the area.

Authorities say that residents with an emergency who can’t reach 911 should use a cell phone if possible to call the police dispatch numbers for help. The numbers are: Gilroy (408) 846-0350; Morgan Hill: (408) 779-2101; unincorporated areas: (408) 299-2311; and San Jose: (408) 277-8900

Search and rescue crews have set up the following locations to respond to residents reporting locations: Uvas and Watsonville roads, near Gilroy; McKean and Bailey roads, near South San Jose and Morgan Hill; Oak Glen and Edmonson roads, near Morgan Hill; Watsonville Road and Highway 152, near Gilroy; New and Church avenues, near San Martin; and Maple and Foothill avenues, near San Martin.

Gilroy police called in eight officers to help patrol the city, more the doubling the force of seven officers on the streets on a typical day, according to Gillio. He said residents should flag down an officer if they need help.

The city of Gilroy is also sending out emergency notifications on cable channel 17 and 1610 a.m. radio and setting up freeway signs directing people to the cable and radio outlets, according to city spokesman Joe Kline. The city also sent fliers to the schools with information about how to report an emergency. Children were asked to bring the fliers home to their parents.

Elsewhere, officials are urging people to go to their nearest fire or police department or local hospital or flag down an emergency vehicle.

“Verizon is completely down; other carriers are intermittent at best,” said Zachary DeVine, a Santa Clara County spokesman.

The damaged fiber optic line owned is by AT&T and leased out to Verizon, DeVine said.

The problem was first reported around 2 a.m. when police in Morgan Hill and Gilroy contacted Santa Clara county dispatchers to report their phones were down. That began a chain of reactions as Santa Clara County officials responded immediately, DeVine said. The county has held over fire crews and has sent additional sheriff’s deputies to Morgan Hill and Gilroy.

Police and fire radios remain operational, meaning field officers are able to get calls from dispatchers and communicate with one another to coordinate aid for anyone reporting to a local fire or police station, DeVine said.

Contact Mark Gomez at mgomez@mercurynews.com or (408) 920-5869.