Take one major U.S. airline, whose Seattle reservations data center went dark Dec. 15 when its backup generator failed to turn on after windstorm-induced blackouts, according to Mark Svenkeson, president of Hypertect Inc., a Roseville, Minn.-based builder of data centers.

"They had all of the right pieces in place; it just wasn't well-implemented, so it shut the business down," he said.

Experts say that data center managers must increase both the diligence and the scope of their outage-proofing efforts, especially since few electrical utilities will be investing in upgrading their fragile infrastructure.

Perhaps the most apparently obvious infrastructure upgrade -- burying existing aboveground electrical lines, especially in areas where wind, hail, heavy snow or falling trees are perennial threats to electrical poles and towers -- still isn't viable or even desirable in most cases, say experts.

"In terms of safety, reliability and especially cost, underground lines are the least preferred choice of engineers," said Rick Pieper, a technical director at Henkels & McCoy Inc., a Blue Bell, Pa.-based engineering firm that builds both above- and below-ground power lines.