A cave is a hole that has been made in soluble terrais by infiltrating whaters. Generally, the solube terrain is lime-stone as is the case of Saint-Elzéar. Undergroung solution and transport start along faults of joint planes and underground chambers usually develop before a sizable opening is made to the surface  by collapsing. In the case of the  Saint-Elzéar cavern, there is a vertical entrance that has a diameter of about 3 meters and that narrows down to a little more than one meter, ending on a rock ledge at a depth of about 13 meters.
Then there is a large chamber, where the talus has accumulated to a depth of about 8 meters. There are other corridors and chambers for a total length of perhaps 80 meters. Suffice to mention here that in aa secondary chamber, bears bone has accumulated in several stratigraphic level in a shallow pit.

These bear possibly werw not dead when they reached the foot of the fall and whandered in the dark before dying from hunger.