The Public Utilities Regulatory Authority shall examine the causes of, and the circumstances connected with, all fatal accidents occurring in the operation of the plant or equipment of any public service company or electric supplier, and such other accidents, whether resulting in personal injury or not, as, in its judgment, require investigation. The authority shall make a record of the causes, facts and circumstances of each accident, within three months thereafter, and as a part of such record shall suggest means, if possible, whereby similar accidents may be avoided in the future. Such record shall be open to public inspection at the office of the authority and a copy thereof shall be mailed to the public service company or electric supplier affected thereby. The authority may by written order extend the deadline for completion of its record in cases where it is not possible to conclude an investigation within the three-month period because of circumstances beyond its control.