It's important to have a written contingency plan, so you will know how the police or other agencies will respond in a worst-case scenario.
It would seem at this point there was no coordination with police officers in the field.
The decision or act of offering so few tickets to so many people can be likened to throwing a small slice of meat to a hungry pack of wolves and this triggered the stampede.
There was a request for police assistance but it was only that. That was the problem.
There is a possible criminal liability here because many people were killed.
