What should I do if the sun umbrella is blown over by the wind and hits passers-by and hooligans Z?

Call the police and wait for handling.

The owner of the sunshade bears the responsibility of poor management, but does not bear the direct responsibility, and compensates the loss party whose responsibility is within the range of 10% (medical care, work, etc. );

The mode of civil liability stipulated in Article 134 of General Principles of Civil Law, Paragraph 2: Eliminating obstruction. The responsibility of the umbrella owner is due to the illegal consequences, and the nature of the responsibility belongs to the state responsibility. This matter belongs to the scope of civil compensation stipulated in the Interpretation Clause of the General Principles of the Civil Law, and the relevant compensation obligations have specific legal interpretations, so it does not belong to the scope of civil mediation, because the premise of civil mediation is that both parties are willing, and once the court decides to exclude it, it will be enforced.