In the event that any sidewalk or street is obstructed in the manner forbidden by § 909.01, notice shall be given to the offending property owner or tenant of such violation, except in cases of emergency, and it shall be the duty of such property owner or tenant of such property to forthwith remove such obstruction. If such property owner or tenant of such property fails or refuses to do so, the city, through the City Engineer, shall have the obstruction removed, and shall charge and collect the cost of such removal from such property owner or tenant.
('71 Code, § 909.02)