220 ILCS 5/8-507
Every public utility shall file with the Commission, under such rules and regulations as the Commission may prescribe, a report of every accident occurring to or on its plant, equipment, or other property of such a nature to endanger the safety, health or property of any person. Whenever any accident occasions the loss of life or limb to any person, such public utility shall immediately give notice to the Commission of the fact by the speediest means of communication, whether telephone, electronic notification, or post.
The Commission shall investigate all accidents occurring within this State upon the property of any public utility or directly or indirectly arising from or connected with its maintenance or operation, resulting in loss of life or injury to person or property and requiring, in the judgment of the Commission, investigation by it, and shall have the power to make such order or recommendation with respect thereto as in its judgment may seem just and reasonable. Neither the order or recommendation of the Commission nor any accident report filed with the Commission shall be admitted in evidence in any action for damages based on or arising out of the loss of life, or injury to person or property, in this Section referred to.
220 ILCS 5/8-507