49 CFR § 225.31 - Investigations.
(a) It is the policy of the FRA to investigate rail transportation accidents/incidents which result in the death of a railroad employee or the injury of five or more persons. Other accidents/incidents are investigated when it appears that an investigation would substantially serve to promote railroad safety.
(b) FRA representatives are authorized to investigate accidents/incidents and have been issued credentials authorizing them to inspect railroad records and properties. They are authorized to obtain all relevant information concerning accidents/incidents under investigation, to make inquiries of persons having knowledge of the facts, conduct interviews and inquiries, and attend as an observer, hearings conducted by railroads. When necessary to carry out an investigation, the FRA may authorize the issuance of subpoenas to require the production of records and the giving of testimony.
(c) Whenever necessary, the FRA will schedule a public hearing before an authorized hearing officer, in which event testimony will be taken under oath, a record made, and opportunity provided to question witnesses.
(d) When necessary in the conduct of an investigation, the Federal Railroad Administrator may require autopsies and other tests of the remains of railroad employees who die as a result of an accident/incident.
(e) Information obtained through FRA accident investigations may be published in public reports or used for other purposes FRA deems to be appropriate.
(f) Section 20903 of title 49 of the United States Code provides that no part of a report of an accident investigation under section 20902 of title 49 of the United States Code may be admitted as evidence or used for any purpose in any suit or action for damages growing out of any matter mentioned in the accident investigation report.