The Public Service Commission, by petitions, applied for peremptory mandamus orders against the defendant to compel it to comply *870with orders of the Commission directing grade crossing eliminations. The defendant interposed answers to the petitions alleging facts tending to justify or excuse its failure to comply with the elimination orders. The court, in the exercise of its discretion, might deny the remedy of mandamus. (Matter of Black v. O’Brien, 264 N. Y. 272.) The defendant should be permitted at a trial to prove the facts alleged to the end that a record may be made upon which the court below might determine whether, in the exercise of its discretion, a peremptory mandamus order should be granted, and to the end that this court on appeal might have before it those facts in determining whether or not the discretion of the court below was properly exercised. The orders should be reversed on the law and facts, with one bill of costs to the appellant. [See Matter of Public Service Commission v. Long Island Railroad Co., post, p. 895.]