During the European Cup Final in May 1985, Liverpool (of England) played Juventus (of Italy) at the Heysel Stadium in Brussels. A stadium wall collapsed after Liverpool fans charged through police toward Juventus fans. Thirty-nine fans died and more than 350 were injured. The incident led British Prime Minister Margaret Thatcher to ban all English football teams from competing for two years in Europe.
Large crowds inspire fans to be more daring and to take part in group activities they would not normally engage in, says Adam Naylor, sports psychology director at the Boston University Athletic Enhancement Center.
“Once we’re in groups and crowds, we tend to get a little more stupid. There’s less individual identification,” Dr. Naylor says.