Why is it important to have knowledge of crowd management and control techniques?

It is important to know how to control a crowd and manage a large group of people for safety sake. A large event can cause any number of accidents, injuries, or even illnesses can happen and there needs to be a plan of action to deal with these. Further to this where you have crowds you have a reason for that crowd.I.e. Sports event. Controlling flow appropriately speeds up footfall traffic, ensures timelines are maintained, improves health and safety risk factors, improves aspects of incident control.