Wisconsin Administrative Code
Office of the Commissioner of Railroads
Chapter RR 2 - Railroads
Section RR 2.12 - Initial reports

Upon occurrence of any accident-incident in Wisconsin involving a railroad, resulting in death, substantial damages or significant hazard to the public, a report shall be made by the railroad involved to the office as soon as practicable but not later than within 24 hours of the occurrence or before 4 p.m. of the first business day following the occurrence.