At the EWUG 2007 Conference we were very fortunate to hear firsthand about how GIS was used at the disaster site.
I know it was a highlight for many at the conference to hear from James Murphy from the City of Minneapolis. He gave a down-to-earth account of how the City's GIS Department handled the I-35W Bridge Collapse. It is a real life story that I'm sure has been played out many times - before a disaster, GIS is just another acronym, afterwards, GIS becomes crucial.
Jim recalled, that soon after the bridge fell, his department went to work - without asking. They just started printing up orthos, lots of them, of the site. Jim then spent several hours trying to get past security to get them to the command center.* Once there, the Minneapolis Police used them for as a basis for security checkpoints.
*A key point made by James was to get the creditntials needed to enter a disaster site. It's not easy, but its still easier to do before a disaster happens than after. Make sure your police/fire/emergancy government department knows who you are and that you have the documentation you need to get past the checkpoint in a real disaster.
Soon after the City was assigned to handle security for the site (other agencies and handled other aspects of the disaster.) The maps then became filled with tons of Post-It notes. James then started digitizing the Post-Its, and their meaning so they won't blow away in the wind. The Command Center end up with it's own GIS tent. GIS was eventually used to geography assign officers to various checkpoints. This was even more important since mutual-aid that was involved. (Mutual-aid is when officers from outside the jurisdiction come in to help.) Many of these officers were not familiar with area, and the maps James and his team proved to be priceless.
GIS really turned out to be a 'common language'. There were lots of acronyms flying around industry jargon, much of which was common to one specific agency on the site. The maps James produced help translate the jargon. The officers/agents, could point to the map and say "Here it is".
ESRI also developed for the City a
very sweet routing tool. It's literally click-click route. This is the best utilization of ArcWeb Services that I've seen yet.