delivered the opinion of the Court.
-This is a bill in equity brought by the defendants in erW to prevent the Pennsylvania Coal Company from mining under their property in such way as to remove thé supports and cause a subsidence of the surface and of their house. The bill sets' out a deed executed by the Coal Company in 1878, under which the plaintiffs claim. The deed conveys the surface, but in express terms reserves the right to remove all the coal under the same, and the grantee takes the .premises with the risk, and waives all claim for damages that may arise from mining out the coal. But the plaintiffs say that whatever may have been the Coal Company’s rights, they were taken away by an Act of Pennsylvania, approved May 27, 1921, P. L. 1198, commonly known there as the Kohler Act. The Court of Common Pleas found that if not restrained the defendant would cause the damage to prevent which the bilUwas brought,, but denied an injunction, holding that the statute if applied to this case would be unconstitutional On appeal the Supreme Court of the State agreed that the defendant had contract and property rights protected by the Constitution of the United States, but held that the statute was'a legitimate exercise^ of the police power" and directed a decree for the plaintiffs. A writ of error was granted bringing the case to this Court.
The statute forbids thé mining of anthracite coal in such way as to cause the subsidence of, among other *413things, any structure used as a human habitation, with certain exceptions, including among them land where the surface is • owned by the owner of the underlying coal. and is distant more than one hundred and fifty feet from any improved property belonging to any other person. As. applied to this case the statute is admitted to destroy previously existing rights of property and contract. The question is whether the police power can be stretched so far.
Government hardly could go on if to some extent values incident to property could not b.e diminished without paying for every such change in the general law. As long recognized; some values are enjoyed under an implied limitation and must yield to the police power. But obviously the implied limitation must have its limits, or the contract and due process clauses .are gone. One fact for consideration ip determining such limits is the extent of the diminution. When it reaches a certain magnitude, in most if not in all cases there must be an exercise of eminent domain and compensation .to sustain the act. So the question depends upon the particular facts. The greatest weight is given to the judgment of the legislature, but it always is open to interested parties to contend that the legislature has gone beyond its constitutional power. ' \
This is the case of a single private house. No doubt there is a public interest even in this,' as there is in every purchase and sale and in all that happens within the commonwealth. Some existing rights may be modified even in such a case. Rideout v. Knox, 148 Mass. 368. But usually in ordinary private affairs the public interest does not warrant much of this kind of interference. A. source of damage to such a house is not a public nuisance even if similar damage.is inflicted on others in.different places. The damage is not common or public. Wesson v. Washburn Iron Co., 13 Allen, 95, 103. The extent of *414the public interest is shown by the statute to be limited, since the statute ordinarily does not apply to land when thé surface is owned by the owner of the coal. Furthermore, it is not justified as a protection of personal safety. That could be provided for by notice. Indeed the very foundation of this bill is that the defendant gave timely notice of its intent to mine under the house.' On the other hand the extent of the taking is great. It pur-. ports to abolish what is recognized in Pennsylvania as an estate in land—a, very valuable estate—and what .is declared by the Court below to be a contract hitherto binding the plaintiffs. If we were called upon to deal with the plaintiffs’ position alone, we should think it clear that the statute does not diselose a public interest sufficient to warrant so extensive a destruction of the defendant’s constitutionally protected rights. '
But the case has been treated as on.e in which the general validity of the act shpuld be discussed. The Attorney General of the State’ the City of Scranton, and thé representatives of other extensive interests were allowed to take part in the argument below and have submitted their contentions here. It seems, therefore, to be our duty to go'farther in the statement of our opinion, in order that it may be known at once, and that further suits should not be brought in vain.
. It is our opinion that the act cannot be sustained as am exercise of the police power, so far as it affects the mining of coal under streets or cities in places where the right to mine such coal has been reserved. As said in a Pennsylvania casp, “ For practical purposes, the right to coal consists in the right to mine it.” Commonwealth v. Clearview Coal Co., 256 Pa. St. 328, 331. What makes the right to mine coal valuable, is that it can be exercised with profit; To Make it commercially impracticable to mine certain coal has very nearly the same effect for constitutional purposes as appropriating or destroying it. This *415we think that we aré warranted in assuming that the statute does.
It is true that in Plymouth Coal Co. v. Pennsylvania, 232 U. S. 531, it was held competent for the legislature to require a pillar of coal to be left along the line of adjoining property, that, with the pillar on the other side of the line, would be a barrier sufficient for the safety of the employees of either mine in case the other should be abandoned and allowed to fill with water. But that was. a requirement for. the safety of employees invited into the mine, and secured an average reciprocity of advantage, that has been recognized as a justification of various laws.
The rights of the public in a street purchased or laid out by eminent domain are those that it has paid for. If in any case its representatives have been so short sighted as to acquire only surface rights without .the right of support, we see no more authority for supplying the latter without compensation than there was for taking the right of way in the first place and refusing to pay for it because the public wanted it very much. The protection of private property in the Fifth Amendment presupposes that it is wanted for public use, but provides that it shall not be taken for such use without compensation. A similar assumption is made in the decisions upon the Fourteenth Amendment. Hairston v. Danville & Western Ry. Co., 208 U. S. 598, 605. When this seemingly absolute protection is found to be qualified by the police power, the natural tendency of human nature is to extend the qualification more and more until at last private property disappears. But that cannot be accomplished in this way under the Constitution of the United States.
The general rule at least is, that.while property may be regulated to a certain extent, if regulation goes too far it will be recognized as a taking. It may be doubted how far exceptional cases, like the blowing up of a house to stop a conflagration, go — and if they go beyond the general rule, *416whether they do not stand as much upon tradition as upon principle. Bowditch v. Boston, 101 U. S. 16. In general it is not plain that a man’s misfortunes or necessities will justify his shifting the damages to his neighbor’s shoulders. Spade v. Lynn & Boston R. R. Co., 172 Mass. 488, 489,. We are in danger of forgetting that a strong public desire . to improve the public condition is not enough to warrant achieving the desire by a shorter cut than the constitutional way of paying for the change. As we already have said, this is a question of degree — ^and therefore cannot be disposed of by general propositions. But we regard this as going beyond any of the cases decided by this Court. - The late decisions upon laws dealing with the congestion of Washington and New York, caused by the war, dealt ..with laws intended to meet a temporary emérgency and providing for compensation determined to be reasonable by ah impartial board. They went to the verge of the law but fell far short of the present act. Block v. Hirsh, 256 U. S. 135. Marcus Brown Holding Co. v. Feldman, 256 U. S. 170. Levy Leasing Co. v. Siegel, 258 U. S. 242.
We assume, of course, that the statute was passed upon the conviction that an exigency existed that would warrant it, and we assume that an exigency exists that would warrant the-exercise of eminent domain. But the question at bottom is upon whom the loss of the changes desired should -fall. So far as private persons or communities have .seen fit to take the risk of acquiring only, surface rights, we cannot see that the fact that their risk has become a danger warrants the giving to them greater rights than they bought.
Decree reversed.