Section 831.2 - Responsibility of the NTSBThe NTSB is required to investigate-
(a) Aviation accidents as described in subpart B of this part;(b) Highway accidents as described in subpart C of this part;(c) Railroad, pipeline, and hazardous materials accidents as described in subpart D of this part; and(d) Any accident that occurs in connection with the transportation of people or property that, in the judgment of the NTSB, is catastrophic, involves problems of a recurring nature or would otherwise carry out the intent of its authorizing statutes. This authority includes selected events involving the transportation of hazardous materials, including their release.