On April 9, 2009, the city of Morgan Hill, California and parts of three counties lost 911 service, cellular mobile telephone communications, land-line telephone, DSL internet and private networks, central station fire and burglar alarms, ATMs, credit card terminals, and monitoring of critical utilities.The development of the internet's communications protocols was sponsored by the U.S. Department of Defense, and they were designed to survive large failures. But it still takes local engineering skill to implement robust networking services.

A Cyber-Attack on an American City

Bruce Perens (from http://perens.com/works/articles/MorganHill/)

Just after midnight on Thursday, April 9, 2009 unidentified attackers climbed down four manholes serving the Northern California city of Morgan Hill and cut eight fiber cables in what appears to have been an organized attack on the electronic infrastructure of an American city. Its implications, though startling, have gone almost un-reported. That attack demonstrated a severe fault in American infrastructure: its centralization. The city of Morgan Hill and parts of three counties lost 911 service, cellular mobile telephone communications, land-line telephone, DSL internet and private networks, central station fire and burglar alarms, ATMs, credit card terminals, and monitoring of critical utilities. ...

Commerce was disrupted in a 100-mile swath around the community, from San Jose to Gilroy and Monterey. Cash was king for the day as ATMs and credit card systems were down, and many found they didn't have sufficient cash on hand. Services employees dependent on communication were sent home.
... The first lesson is what stayed up: stand-alone radio systems and not much else. Cell phones failed. Cellular towers can not, in general, connect phone calls on their own, even if both phones are near the same tower. They communicate with a central switching computer to operate, and when that system doesn't respond, they're useless. But police and fire authorities still had internal communications via two-way radio. Realizing that they'd need more two-way radio, authorities dispatched police to wake up the emergency coordinator of the regional ham radio club, and escort him to the community hospital with his equipment. Area hams dispatched ambulances and doctors, arranged for essential supplies, and relayed emergency communications out of the area to those with working telephones.

... The development of the internet's communications protocols was sponsored by the U.S. Department of Defense, and they were designed to survive large failures. But it still takes local engineering skill to implement robust networking services. Most companies stop when something works, not considering whether or how it will work in an emergency.