In experiments involving nearly 1,000 participants carried out by the Jülich Research Center and the University of Siegen, they collected huge amounts of data on how people react in crowds when chaos breaks out. For three days, the test subjects were involved in a series of scenarios, walking through artificially constructed bottlenecks, simulated intersections and adjustable emergency exits. The researchers want to know the best way to construct buildings, stadiums and exits to help improve safety at football games and other big gatherings.