 In 1885 the park was unroofed, and was instead used as an outdoor exposition, with an Edison-designed electric trolley line transporting visitors around the park to see such sites as a roller coaster, bicycle trails, and an art museum surrounded by a lake.The park's future became less certain after the murder of the family's patriarch, Alfred DuPont.A bachelor who enjoyed all the good things that late Victorian culture had to offer, he was a habitué of the night life.