The Supreme Court held that a Pennsylvania law prohibiting underground mining that causes damage to surface structures does not violate either the takings clause or the contracts clause.
In 1966 the Pennsylvania legislature enacted a law prohibiting coal mining that caused subsidence damage to preexisting public buildings, dwellings, and cemeteries. Based on Pennsylvania Coal Co. v. Mahon
Speaking for a 5-4 majority, Justice John Paul Stevens
Lucas v. South Carolina Coastal Council
Nollan v. California Coastal Commission
Pennsylvania Coal Co. v. Mahon