This article is from the Aviation FAQ, by Geoffrey G. Peck firstname.lastname@example.org with numerous contributions by others.
The NTSB has a web page which contains synopses, statistics, reports,
and publications related to aviation:
Accident synopses (preliminary, factual, and final) are organized on
a month-by-month basis on the page:
There are several types of reports available: preliminary reports,
which are usually available within a month of the accident; factual
reports, which are usually available 7 months to 1 year following the
accident; and probable cause reports, which may take up to 2 years.
Copies may be obtained from General Microfilm, 11141 Georgia Avenue,
Suite B6, Silver Springs MD 20902; phone 301/929-8888. You'll need (a)
the aircraft registration number, or (b) the date and location of the
accident, or (c) the name of the pilot for accidents which occurred
prior to 1978. [Thanks to _Flying_ magazine, June 1993, for this info.]