Crystal Ann Arensdorf, 21, was last seen in the early hours of July 4, 2001, inside Knickers Saloon in Dubuque, Iowa. She had spent the evening watching fireworks with her sister and later went to the bar with friends; she was seen at about 2:00 a.m. but never seen leaving. Her car, keys, and money were left behind and she did not show up for work the next day, prompting her family to report her missing.

Investigators questioned two brothers, Steven and David Peacock, who had been at the bar that night; they were not charged. The bartender, Robert Mootz, admitted serving alcohol to Crystal despite her being underage and said they had planned to share a cab to East Dubuque, Illinois, but Crystal never left with him. Searches, including one at Leisure Lake, turned up no significant evidence.

The disappearance remains unsolved and the family continues to seek answers and asks anyone with information to contact law enforcement. Did anyone who was in or around Knickers Saloon that night remember seeing Crystal leave or get into a cab?