What is the casualty number of the accident?

Four people were killed and more than 50 injured when fans rushed to get into a stadium in Chicago yesterday where the British pop group Fantasy were giving a concert. The incident occurred when gates were opened to admit a huge crowd of young people waiting outside the stadium for the sale of tickets unreserved. People were knocked over in the rush and trampled underfoot as the crowd surged forward. The concert later went ahead as planned with Fantasy unaware of the accident. A police spokesman said that they had decided to allow the concert to proceed in order to avoid further trouble.