 The only significant evidence that was found were two decompression tanks filled with plain air (rather than the standard mixtures of gases normally used for diving in such conditions).The discovery of the tanks raised suspicions further because, in addition to being filled with the wrong type of gas, they were found just outside the entrance to the cave, though experienced divers know to place tanks close by to the areas they'll be exploring further down, thus keeping them within easy reach in case of emergency.This was seen as odd, considering that McDaniel was last seen deep inside the cave, attempting to bypass the gate to the restricted section by a diving staff member exiting the cave, who then unlocked it for him despite his lack of certification or diving partner.