44. An easement is extinguished where the servient heritage is by superior force so permanently altered that the dominant owner can no longer enjoy such easement: Provided that, where a way of necessity is destroyed by superior force, the dominant owner has a right to another way over the servient heritage; and the provisions of section 14 apply to such way. Illustrations (a) A grants to B, as the owner of a certain house, a right to fish in a river running through A's land. The river changes its course permanently and runs through C's land. B's easement is extinguished. (b) Access to path over which A has a right of way is permanently cut off by an earthquake. A's right is extinguished.