The first objection raised by the plaintiff to the action of the county commissioners and the record of their proceedings is that they had no jurisdiction in the premises.
By the statutes the commissioners have original jurisdiction of all questions arising on the construction of railroads across highways. They may, on petition by a railroad laid out across a highway, determine whether the railroad shall cross under, over or at grade, and what alterations are necessary in the highway, and the manner and time of making them. Gen. Sts. c. 63, §§ 48, 62; St. 1865, c. 239. But the plaintiff contends that by the St. 1865, c. 170,* the defendant corporation was in terms empowered to cross Main Street in Clinton at grade; that the discretion lodged in the commissioners by the Gen. Sts. and St. 1865 could not be exercised; that they had no power to refuse or to grant, and therefore could not determine the manner in which the crossing should be constructed; in other words, that the Legis*56lature by this special act intended to give authority to the defendant to make all necessary alterations at this crossing without application to the commissioners. If this is the construction of St. 1865, c. 170, it is difficult to see how the plaintiff can maintain this action, as the railroad would then have had the right to make of its own motion the alleged changes, and the remedy of the plaintiff would have been by application to the commissioners for damages under Gen. Sts. c. 63, § 21. -But this is not the construction of that statute. It simply limits the power of the commissioners and abridges the inquiry to be entered into before them. It declares in substance that the railroad, having the power to cross the highway, may do so at grade, but what alterations are necessary in the way, and the manner of making them, are questions untouched by the statute. These are left to be determined by the existing provisions of law and by the tribunal clothed with the necessary powers. It is not to be presumed that the Legislature intended to change the existing law any further than the words of the statute indicate. We therefore are of opinion that the petition was properly brought, and was within the jurisdiction of the commissioners.
The second objection is to the record of the commissioners ; that it does not show that they complied with the provisions of law, and that it is defective in its recitals and statements as to notice, adjudication of public necessity, and many other particulars, and therefore that it affords no justification to the defendant. The plaintiff contends that these questions can be passed upon in an action at law. We do not propose to consider these several defects, because we think the record cannot be passed upon in this action. Brimmer v. Boston, 102 Mass. 19, 23.
The county commissioners constitute an inferior court charged with certain ministerial and judicial duties. On all matters of fact properly submitted to them, and in the legal exercise,of their discretion, their decisions are final and conclusive. If they fail to perform a legal duty, either judicial or ministerial, mandamus lies to compel them to do so. Carpenter v. Bristol, 21 Pick. 258. If in the performance of a legal duty they have committed an error in law, or have failed to proceed in all respects accord*57ing to law, certiorari lies to quash, affirm, or amend their proceedings. Gen. Sts. c. 145, § 9. It is unnecessary to cite the numerous cases to this point. In these two forms of procedure only, according to the well settled practice in this Commonwealth, can their action be controlled or annulled. When, therefore, they have acted in the regulation of railroad crossings over highways, which is a matter within their jurisdiction, their record, ordering in what manner the crossing shall be constructed, and what alterations shall be made in the way, is conclusive in an action at law upon all parties, and can only be inquired into upon a writ of certiorari.
A petition for a writ of certiorari to quash proceedings of county commissioners is addressed to the judicial discretion of the court; and the whole record is to be considered and examined. The writ is not granted for formal or technical errors, or for substantial errors where rights are not prejudiced thereby, or for formal defects of notice, or where the proceedings have been long acquiesced in by the parties in interest and other rights have intervened, or where the consequences would be ruinous or mischievous if the proceedings were quashed, or where parties cannot be placed in statu quo. Ex parte Miller, 4 Mass. 565. Gleason v. Sloper, 24 Pick. 181. Rutland v. County Commissioners, 20 Pick. 71. Hancock v. Boston, 1 Met, 122. Cobb v. Lucas, 15 Pick. 1, 4. And under Gen. Sts. c. 145, § 9, this court may enter such judgment or order as law and justice may require ; or nay vacate the illegal proceedings, and order the commissioners themselves to correct the irregularity. Lowell v. County Commissioners, 6 Allen, 131. Haverhill Bridge v. County Commissioners, 103 Mass. 120.
It is obvious that to try the validity of such a record, or of so much of it as is presented in an action at law, when the court is limited in its powers, would be to subvert the well established practice, and we might have the anomaly presented of this court declaring proceedings invalid in an action at law, and refusing to quash them on a petition for certiorari.
But the plaintiff’s right of action does not depend alone upon want of jurisdiction in the county commissioners, or upon alleged *58irregularity in their proceedings. The declaration alleges that the defendant wantonly, negligently and improperly placed large quantities of earth upon the street, and graded the same in such a careless, negligent and improper manner as greatly to damage and incommode her in the occupation of and access to her estate. Under this allegation she offered evidence at the trial tending to prove that the way was raised higher than was authorized by the order of the commissioners, thereby causing greater damage to her estate than would otherwise have been done.
This is a cause of action wholly independent of the defendant’s liability for acts done within the authority conferred by the order of the commissioners. For all damage done to the plaintiff within the limits of that authority, the only remedy is by an application to the county commissioners. Gen. Sts. c. 63, § 21. The measure of compensation in such proceedings is the injury which was caused by raising the street six feet and four inches, according to the authority given by the order of the commissioners. To this extent the corporation may claim the protection of the authority under which it acted, as against an action at common law. But for anything done in excess of that authority, or unskilfully or negligently done within it, to the special injury of the plaintiff, she may have her action of tort. The plaintiff would otherwise be without remedy. Wheeler v. Worcester, 10 Allen, 591. Mellen v. Western Railroad Co. 4 Gray, 301.
The evidence offered may show special and peculiar damage to the plaintiff. The wrong is none the less actionable because it is committed in such a way that the defendant may be liable to a public prosecution. Both modes of redress may exist and be pursued at the same time. Commonwealth v. Vermont Massachusetts Railroad Co. 4 Gray, 22. Wesson v. Washburn Iron Co. 13 Allen, 95.
Nor is it a question of the mode in which a compliance with the order of the commissioners is to be enforced when only public interests are involved. The protection of such interests may well be left to public prosecution, or to such proceedings in equity or otherwise as the statutes may require.
*59It is not necessary to inquire whether the verbal acceptance of the work by the county commissioners was a valid acceptance. They were acting in this respect as public officers, in reference to public convenience only. An acceptance, however formal, cannot deprive the plaintiff of a right of action founded upon a private injury, whatever may be its effect upon public rights.
The conclusion therefore is, that the county commissioners had jurisdiction; that their record cannot be inquired into in this action; but that the plaintiff can maintain her action, and try the questions whether the street was raised higher than the order of the county commissioners directed, and what special damage resulted to her therefrom. The verdict, therefore, must be set aside and a New trial granted.
Section 1. The Agricultural Branch Railroad Company is hereby authorized to construct its track across the track of the Worcester and Nashua Railroad Company, in the town of Clinton, and over Main and Water streets in said town, at grade; provided, however, that if said company shall build its track across said Water Street at grade, it shall erect and maintain across said street, on the easterly side of said railroad track, a gate, and cause the lame to be closed while the trains are passing said street.
Section 2. This act shall take effect' upon its passage.
By St. 1867, c. 153, the name of the Agricultural Branch Railroad Company was changed to the Boston, Clinton and Fitchburg Railroad Company.