When it comes to handling disasters there are many companies with substantial capacities that can respond at a time of need. If the event is widespread, they will probably all be quite busy and the response will need to be shared among all the affected institutions in the geographic proximity
There are some other powerful resources that everyone on this Forum should be aware of. The American Institute for Conservation of Historic and Artistic works (AIC) maintains the ultimate reference page on the topic: http://cool.conservation-us.org/bytopic/disasters/
The AIC is the national organization conservation professionals and it also maintains a directory of peer reviewed conservators who can be called upon in cases of emergency or routine services. The Directory is searchable by geographic region as well as field of specialization and can be accessed at: http://www.conservation-us.org/index.cfm?fuseaction=Page.viewPage&pageId=495 .
AIC-CERT is the emergency response arm of the AIC. For information visit http://www.conservation-us.org/index.cfm?fuseaction=Page.viewPage&pageId=695 . The Collection Care Network, (CCN), is a brand new initiative of the AIC and it will truly help in the task of connecting to collections. For information visit: http://www.conservators-converse.org/2012/01/aic-collection-care-network-charge/ .
There are a great many conservators in private practice (CIPP) across the country and we have our own group within the AIC. I happen to be the Chair of CIPP currently and have occasion to help institutions find a qualified conservator for any given task. Feel free to contact me in case of need.
Lastly, the very best advice I can provide is to cultivate volunteers in the community, train them and prepare them to help out at a time of need. They have a vested interest in local institutions and will make the effort.
George Schwartz george@ConservArt.com