Findings into the deaths of Darrin Spivey (35) and his son Dillon Sanchez (15) showed they died after their tanks ran out of air.
The divers equipment showed they dived to 233 feet (71m) using air alone in their tanks. According to rescue diver Eric Deister, the men should have been using a trimix combination for their breathing supply, not air alone. The divers believe Spivey and Sanchez, neither of whom was certified in cave diving, lost track of time while exploring the caverns at Eagle Nest Sink. Spivey was certified in open diving, and his son had no certifications.