FILE - A security guard and an unidentified man look at an area with shows and clothes strewn around where several people were killed and others injured, as they were caught in a surging crowd entering Cincinnati's Riverfront Coliseum for a Who concert on Dec. 3, 1979. The crowd deaths at a Houston music festival on Friday, Nov. 5, 2021, have added to the long list of people who have been crushed at a major event. Such tragedies have been occurring around the world for a long time at concerts, sports events and religious gatherings. (AP Photo/Brian Horton, File)