"What nobody anticipated was complete isolation for a week," said Don Chenoweth, CIO at East Jefferson General Hospital in Metairie, La., which borders New Orleans.

East Jefferson, one of three hospitals to stay open during Katrina and its aftermath, was built to survive. The hospital opened in 1971 and incorporated the lessons learned from Hurricane Betsy, which had torn up the region six years earlier. The hospital was built at sea level, which is relatively high ground considering that there are adjacent areas six feet below sea level. The facility has 15 generators, redundant communications lines and its own water well.

On his computer, Chenoweth pulls up photos of Katrina showing the hospital completely surrounded by water. Water literally came up to some doors but didn't make it into the building. When the storm cut external power, East Jefferson's generators kicked in, but then wind and water damage knocked out the electronics of the generator that supplied its data center. Battery supplies gave IT workers enough time for an orderly shutdown, Chenoweth said. Another generator failure knocked out the data center's air conditioning. Fortunately, the hospital's well continued to work, enabling people to take showers and flush toilets.

East Jefferson's data center was out of commission for four and a half days, Chenoweth said. External voice communications were knocked out, but with the exception of a 12-hour period, the hospital had Internet access.

One thing Chenoweth discovered -- and other IT managers said they found as well -- was that it was easier to make a call on cell phones that didn't use a local area code because calls are routed differently on the nonlocal cell phones. Consequently, the hospital has purchased a number of cell phones with Baton Rouge area codes for emergency use.