A Knokke resident filmed the apocalyptic scenes on Saturday afternoon.
Shortly before 2pm on Saturday, the sky turned threateningly dark over Knokke, Belgium.
Amateur footage shows how umbrellas suddenly seemed to have a life of their own, and how concerned clients started to flee the terraces.
Staff members tried to save, admittedly in vain, what they could. When the storm hit, many customers were seated outside. Fortunately nobody suffered severe injuries.
The worst was already over after a couple of minutes. Material damage, however, is significant, the manager of the restaurant told the Het Laatste Nieuws newspaper.