Opinion by
Mr. Justice Jones,The plaintiffs are the owners by the entireties of a dwelling at 1522 Lowrie Street, Pittsburgh, which they were occupying as a residence in February, 1948, when the house was partially destroyed by a gas explosion in the cellar. Each of them also suffered serious personal injury. They instituted the instant action in trespass against the City of Pittsburgh to recover damages for their personal injuries and property loss, alleging that the explosion, which caused the damage, was due to negligence of the City. The City impleaded two additional defendants as to whom compulsory non-suits were entered at trial and the case went to the jury against the City alone. The trial resulted in a disagreement of the jury. After the City’s motion for judgment on the whole record was denied, the case came on for retrial at which the jury returned a verdict for the defendant generally. The court en banc, being of the opinion that the question of the plaintiffs’ contributory negligence had erroneously been submitted to the jury, granted the plaintiffs’ motion for a new trial and, from that order, the City took this appeal.
The appellant’s contention is that the matter of the plaintiffs’ contributory negligence was properly left to the jury and that the action of the court en banc, based on the opposite view, was a mistake of law remediable by this court on review.
At the retrial, the plaintiffs introduced evidence which established the folloAving set of circumstances. *258Lowrie Street in Pittsburgh is a wide, heavily travelled thoroughfare, paved with Belgian blocks, and accommodates within its cartway a double set of street car tracks. A main gas line runs longitudinally under the surface of the street between the tracks. There was connected to the main gas line, opposite the plaintiffs’ property, a feeder or service line which lay three and one-half feet below the surface of the street and ran to the plaintiffs’ house which it entered through the front cellar wall. The earth surrounding the feeder line was firmly packed and the cellar wall was tight around the pipe. Immediately inside the wall there was fitted to the feeder line, in an upright position, a right-angle elbow from the top of which a gas line was run to the cellar ceiling and, thence, horizontally along the ceiling. As the learned trial judge correctly related the facts in his opinion for the court en banc, — • “For about a year before the explosion, and during intermittent periods for several years before that, there was a hole in the surface of Lowrie Street between the two sets of car tracks in front of plaintiffs’ house. It was about as wide as the ‘dummy’ [the space between the tracks], several feet long and as deep as eight inches at one point. Its contour and dimensions were such that trucks were violently jolted when their wheels traversed the hole. The contact of wheels and hole caused vibrations in plaintiffs’ house. These could be felt by the occupants; at times the electric lights ‘blinked’, windows rattled and the victrola needle ‘jumped the groove’. . . . Vibrations caused by truck wheels and the hole were carried by the firm earth beneath the street surface causing vibratory stress upon the ‘elbow’ in the service line just inside plaintiffs’ cellar wall. This long continued stress caused a ‘metal fatigue crack’ in the ‘elbow’. Gas escaped, through this crack, accumulated in the cellar and caused the ex*259plosion.” Although the plaintiffs had averred in their complaint that they had notified the City of the unusual nature and extent of the vibrations, they offered no evidence whatsoever at trial to support the averment.
The trial court instructed the jury, inter alia, that the City, even if it had negligently failed to repair the street, was not negligent as to the plaintiffs in respect of their property, and therefore not liable to them, unless the resultant harm was such that it could or should have reasonably been foreseen by the City. The court then observed to the jury, “I don’t see any evidence in this case to warrant a finding that the plaintiffs were contributorily negligent. ... on the evidence in this case you could not make a finding to support the conclusion that the plaintiffs were contributorily negligent.” However, at the conclusion of the charge, counsel for the City requested the court to instruct the jury with respect to the matter of the plaintiffs’ contributory negligence. To this, the court acceded and thereupon charged the jury that the plaintiffs were aware of the unusual vibrations for some five years prior to the explosion and that, if the crack in the elbow of the gas line inside the cellar resulted from the transmittal of vibrations caused by vehicles hitting the hole in the street, it was for the jury to say whether the plaintiffs “used the care of a person of ordinary prudence with reference to the risk of damaging this pipe and causing a gas explosion due to those vibrations. If you feel that they did not use the care of a person of ordinary prudence to protect themselves against injury, then you could conclude that they were guilty of contributory negligence. If they are guilty of contributory negligence, then they could not recover in this case whether the City was negligent or not.”
*260In awarding the plaintiffs a new trial, the court en banc stated in its opinion that “The charge as to contributory negligence, however, was in error. Evidence binding on plaintiffs revealed that they had knowledge of the vibrations caused by the hole and traffic for a number of years. In effect, the charge permitted the jury to find contributory negligence from this knowledge and the explosion. The decisive matter was whether plaintiffs, with knowledge of the vibrations, acted as persons of ordinary prudence would have acted to protect themselves from the risk involved. The burden was upon defendant to show what this conduct was, plaintiffs’ testimony not having disclosed it. So far as the testimony goes, plaintiffs may have taken all the precautions that the man of ordinary prudence would have taken. The issue of contributory negligence should not have been submitted at all.”
The plaintiff in a negligence action, of course, has the burden of establishing by a preponderance of the evidence the fault of the defendant as the proximate cause of the injury in suit. On the other hand, the burden of proving the plaintiff guilty of contributory negligence falls squarely on the defendant. But, while the plaintiff has no duty to show affirmatively his freedom from fault, still he may not recover if the evidence in his own case convicts him of contributory negligence. As already indicated, the court en banc recognized that evidence binding on the plaintiffs revealed that for several years prior to the explosion they had knowledge of the nature and intensity of the vibrations and, further, that there was no evidence whatever to show whether the plaintiffs had or had not taken any precautions to insure their own safety. So far as the evidence discloses, the plaintiffs, with knowledge of the character of the vibrations, did nothing to guard against possible injury and loss. The real issue, *261then, is whether the jury should have been permitted to consider whether the plaintiffs’ failure to take proper action with respect to the alleged vibrations constituted contributory negligence.
As the verdict for the defendant could have resulted, under the instruction of the trial judge, from the jury’s finding the plaintiffs guilty of contributory negligence, we shall for present purposes assume that the jury could have reasonably concluded that the explosion in the plaintiffs’ house from the gas leakage in the cellar was a consequence within the foreseeable risk created by the City’s long-continued neglect of the hole in the middle of Lowrie Street. If that were not so, then the case should not have been submitted to the jury at all since the plaintiffs would have failed to prove the City guilty of causative negligence. But, recurring to the question of contributory negligence, awareness of the possibility of harm inside the plaintiffs’ house from the vibrations due to the hole in Lowrie Street is as imputable to the plaintiffs as to the City. Indeed, the plaintiffs were, if anything, in a much better position to appraise the possibility of consequent harm from the vibrations than was the City. The City was, of course, chargeable with constructive knowledge of the existence of the hole in Lowrie Street. But, the plaintiffs, on the other hand, had actual knowledge of the unusual nature and intensity of the vibrations caused by vehicles striking the hole in Lowrie Street. Yet, despite the manifestations inside the house, from the outside jolting, to which the plaintiffs testified, they stood idly by for at least a year prior to the explosion without notifying the City of the condition known to them.
As §463 of the Restatement, Torts, defines it, “Contributory negligence is conduct on the part of the plaintiff which falls below the standard to which *262he should conform for his own protection and which is a legally contributing cause, cooperating with the negligence of the defendant in bringing about the plaintiffs harm.” See, also, Kovalish v. Smith, 357 Pa. 219, 222, 53 A. 2d 534. Contributory fault may stem either from a person’s careless exposure of himself to danger or, as here, from his failure to exercise reasonable diligence for his own protection: see Restatement, Torts, §466. From the general verdict for the defendant in the instant case, it is not possible to say whether the jury, in denying the plaintiffs recovery, concluded that the injuries were not within the scope of a foreseeable risk or whether the plaintiffs neglected to take the precautions for their own safety which a person of ordinary prudence would have taken. But, in any event, whether the jury’s verdict was based on the one reason or the other, the learned trial judge did not err in permitting the jury to pass upon the reasonableness of the plaintiffs’ conduct in the circumstances.
On analogous principle, where a passenger in an automobile, who has an opportunity to control or influence the driver’s conduct, sits by without protesting the negligent operation of the car and permits himself to be driven to his injury, his negligence may bar a recovery. See Janeway v. Lafferty Brothers, 323 Pa. 324, 330-331, 185 A. 827; Nutt v. Pennsylvania Railroad, 281 Pa. 372, 376-377, 126 A. 803; and Minnick v. Easton Transit Co., 267 Pa. 200, 204-205, 110 A. 273. Likewise, a plaintiff, who observes a fire burning on land adjoining his and fails to notify the adjoining owner of the threatening condition and makes no attempt to safeguard his own property, may be deemed guilty of contributory negligence as a matter of law (Hunter v. Pennsylvania Railroad Company (No. 2), 45 Pa. Superior Ct. 476) and, at least, the question of his contributory negligence is a matter for the *263jury to resolve: Hunter v. Pennsylvania Railroad Company (No. 1), 45 Pa. Superior Ct. 468, 475. So, here, the question of the plaintiffs’ contributory negligence was for the jury.
There is no merit in the plaintiffs’ contention that, inasmuch as the City is charged with constructive notice of the defect in Lowrie Street and had a consequent duty to investigate the situation, it was unnecessary for the plaintiffs to have given the City actual notice of the resultant conditions inside their house. Even assuming that the City could be found guilty of legally causative negligence in the premises, and apart from the obvious distinction between real and imputed knowledge, it was, nevertheless, for the jury to say whether reasonable men in the plaintiffs’ position would have communicated to the City the fact of the interior effect, known to them, of the unusual vibrations from the street.
The order granting a new trial is reversed and judgment is here entered on the verdict for the defendant.