It shall be the duty of the owner, manager or person in charge of every hotel, restaurant, hospital, church, school, theater, public building, store or any mercantile establishment of any kind in the City to notify the Fire Department as to the existence and location of any fire upon such premises immediately upon discovering the existence of such fire. However, this section shall not be construed to prohibit the owner, manager or person in control of such establishment from using all diligence necessary to extinguish the fire on such premises prior to the arrival of the Fire Department.
(1956 Code Sec. 941.02)