Tributes poured in on Saturday for Riley O'Neil , a Chicago city employee who led its bike parking program for years after he was struck and killed while biking in Bridgeport. Witnesses told NBC Chicago that O'Neil was riding in a bike lane when the driver of a car opened a door in front of him, causing him to lose control before he was struck by a semi-truck driver who was traveling behind him before the initial collision. A mangled bike could be seen in the roadway in the aftermath of the cras