A tragedy occurred in the cave on June 20, 1988. Cave divers John Schweyen and Roberta Swicegood were surveying and mapping the cave from the Arch Spring end, and they found two sumps. The second was extremely long and deep: about 305 meters (1000 feet) long and 32 meters (105 feet) deep underwater. After Schweyen left the cave, Swicegood went back in for a solo dive. When she did not return, several divers attempted to rescue her but were unsuccessful. Her body was recovered four days later. She had apparently lost her guideline in the second sump; with visibility near zero, she was unable to find the line again before her air supply ran. In the aftermath of this tragedy, the Western Pennsylvania Conservancy (who owned the cave at that time) banned further cave diving indefinitely. Cave diving remains forbidden at Tytoona without express written permission from the Tytoona Cave Preserve management.