Edward Irby was 46 when he disappeared at Fort Knox Mine near Fairbanks, Alaska, on April 13, 1997. He was in training to operate a bulldozer; the machine ran down a steep slope and plunged into a tailings pond. No one witnessed the incident. An underwater inspection of the bulldozer suggested Irby had escaped the enclosed cab, but he was never found despite immediate search and rescue and divers from the Alaska State Troopers working in appalling, muddy conditions.

No trace of Irby turned up that summer, leaving his family without closure. A 1997 attempt by his wife to have him declared legally dead failed for lack of evidence. Six years later a jury found he had died in a workplace accident. The mining company contested death benefits, alleging he might have faked his death without producing evidence; after appeals the state Supreme Court ordered the company to pay the benefits.

Anyone who worked at Fort Knox Mine in April 1997 or has information about the pond area is asked to come forward.