EM-DAT, compiled by the WHO Collaborating Centre for Research on the Epidemiology of Disasters (CRED), catalogues disasters around the world since 1900. See the explanatory note for the definition of a disaster etc.
To make a request for raw data, click "Database" and then "DISASTER LIST", and follow the instructions.
Although it is primarily a cross-country data set, it contains the name of sub-national regions affected by disasters. By geo-referencing them, the data can become a sub-national one. This presentation slide discusses issues in geo-referencing the EM-DAT data.
Used by Stromberg (2007). Besley and Persson (2011) use this data to construct an exogenous shock to the real wage or the opportunity cost of labor.