(1) Whenever a menace to the public health or safety is created by a natural disaster or similar calamity such as flood, storm, fire, earthquake, explosion, accident, the Mayor or the Chief of Police may close the area where the menace exists for the duration thereof by means of ropes, markers, or guards to any and all persons not authorized by the Mayor or the Chief of Police to enter or remain in the enclosed area.

(2) If the calamity creates an immediate menace to the health, safety, or welfare of those residing in an area where a menace exists, the Mayor or the Chief of Police may close the area and require the evacuation of buildings or other structures pursuant to the conditions set forth in this Section.

(3) The Mayor or the Chief of Police may close the immediate area surrounding any emergency field command post.

(4) Any unauthorized person who willfully and knowingly enters an area closed pursuant to Subsection (1), (2) or (3) of this Section, and who willfully remains within the area after receiving notice to evacuate or leave shall be guilty of a misdemeanor and is subject to immediate arrest.