Federal law requires spills, explosions, and other safety-endangering incidents involving hazardous materials to be reported to the Pipeline and Hazardous Materials Safety Administration (PHMSA).
Specifically, “each person in physical possession of a hazardous material at the time that any of [certain types of incidents] occurs during transportation (including loading, unloading, and temporary storage) must submit a Hazardous Materials Incident Report on DOT Form F 5800.1 […] within 30 days of discovery of the incident”.
These “5800.1” forms include details about the location of the incident, mode of transportation, parties involved, hazardous materials involved, causes of failure, fatalities, injuries, financial cost, and more.
PHSMA publishes the submitted reports through an online portal. That portal, however, is brittle and does not provide a straightforward mechanism to download the full set of submitted reports.
The Data Liberation Project has fetched, and is updating daily, all reports available through that portal, and making them available in bulk for further analysis.