225 ILCS 710/14
Whenever a serious accident occurs in or about any mine, notice thereof shall be given promptly by telephone or telegraph, followed by a notice in writing, to the inspector by the superintendent or other person having immediate charge of the work at the time of the accident. The words "serious accident" shall be construed to mean, for the purposes of this Act, accidents resulting in such injuries as, in the opinion of an accredited physician, may result in the injured person being incapacitated from work for at least 14 days. Upon receiving such notice the inspector shall, if feasible and if the nature of the accident shows it to be necessary, proceed to the scene of the accident with all convenient speed and investigate fully the cause of the accident, and, within 20 days thereafter, shall file the result of such investigation as a report in the office of the inspector. Whenever the inspector cannot proceed as above to the scene of the accident, the person in charge of the mine shall be so informed by the inspector and such person in charge shall obtain sworn statements of those who witnessed the accident, or if no one was present at the time of such accident the person in charge shall obtain the sworn statement of those first arriving upon the scene. Such statements shall give, as far as possible, the details of the accident, the facts leading up to it, and its probable cause; such sworn statements shall immediately thereafter be sent to the inspector, who shall file the same in his office as public records.
225 ILCS 710/14