GenDisasters.com is a genealogy site that contains information on the historic disasters, events, and tragic accidents our ancestors endured, as well as, information about their life and death. Database and records searchable by surname as well as by the name of a disaster or by Year or by U.S. State. A separate section of the site contains information about disasters in Canada.
I don’t think the site has every disaster but it certainly describes many. If you are wondering why a family member abruptly disappeared, you might want to check this site. Also, some families had to relocate after a disaster, such as floods or late spring blizzards that destroyed newly-planted crops.
GenDisasters may be found at http://www3.gendisasters.com.