—This action was brought by plaintiffs, who were tenants occupying the first story and basement of a store in this city, against defendant, the occupant of the second and upper stories, for injury to their goods occasioned by an overflow of water on to their premises from defendant’s premises, occasioned, as is alleged, by the negligence of the defendant or his agents or servants, whereby plaintiffs’ goods were damaged and they were interrupted in the enjoy*330ment of their premises and business, and put to expense in removing and selling the damaged goods.
The answer denied the occurrence of any such accident in the manner charged, and alleged that if any damage was caused thereby it was the result of plaintiffs’ negligence; it also set up that plaintiffs; at the time of the injury had under control the stop-cock connecting with the water flowing on to defendant’s premises, and controlling its flow, and that they had it in their power to control it at pleasure, and to prevent its flow on to their premises from those of the defendant, and if any injury was caused thereby, it was through their negligence in failing to make use of the stop-cock, or in failing to make proper use thereof.
The evidence adduced at the trial showed that plaintiffs had on their premises such a stop-cock entirely controlling the flow of water up on to defendant’s premises; that on the night of the accident it was not turned so as to cut off the water from its upward flow; that another cock on defendant’s premises that allowed the water to flow into and pass off through a urinal was left open on the night of the occurrence, and that by reason of the accidental stoppage of the waste holes in the urinal by a piece of segar, the water being left running, overflowed the urinal and ran down on to, and through, the floor and into plaintiffs’ premises below, occasioning the injury complained of, and that this occurred during the night time when all the parties, as was customary, were absent from the premises. The evidence established the neglect of the defendant in allowing the water-cock on their premises to remain open and the flow of water through the urinal tobe obstructed by apiece of segar, as the immediate cause of the injury.
The matter first presented for consideration upon the exceptions is the refusal of the judge to admit evidence tending to show contributory negligence on the part of the plaintiffs in omitting a service or duty which it was claimed they had previously assumed and performed until the night of the accident, in stopping off the flow of water up to defendant’s premises by the stop-cock on their premises. The averment that the injury was caused by plaintiffs’ failure to use these means of avoiding *331such an accident, is set up in the answer. The judge appears to have regarded this alleged assumption of duty on the part of the plaintiffs as matter that ought to have been specially pleaded, and ruled that the testimony offered as to plaintiffs’ negligence, founded on their voluntary agreement, was inadmissible. Various offers tending to establish such assumption of duty, were made, but rejected, and in my opinion, erroneously.
In an action of tort for negligence, evidence that the acts or omissions of the plaintiffs contributed to the injury, is admissible under a general denial that the injury complained of was occasioned by the defendant. The right of recovery depends on plaintiffs’ establishing, at least b y prima facie proof, that he in no respect by his own negligence contributed to the injury, but that it was occasioned solely by the defendant’s acts (Button v. Hudson R. R. Co. 18 N. Y. 248; McDonell v. Buffum, 31 How. Pr. 154; Deyo v. N. Y. Central R. R. Co. 34 N. Y. 9 ; Grippen v. Same, 40 N. Y. 34).' Such exemption from liability was equally available to this defendant, if the injury complained of was in any way attributable to plaintiffs’ neglect in turning off the water by the main stop-cock on their own premises. Whether regarded as a primary duty arising from having the entire control, or as one they had gratuitously assumed and were in its ordinary performance for the accommodation of the defendant (Ed. on Bail. 94). One assuming the voluntary performance of an act or duty for another, engages for such skill and attention as it ordinarily requires, and if it be in respect to a matter for which the defendant is under contract or obligation with himself, he cannot make claim for any malfeasance or neglect to which he has himself been a party or contributed. In an action of tort for negligence in performance of such duty, the fact that plaintiff contributed to the injury would be available under a general denial that it was caused by the defendant’s neglect, and without special defense of such secondary intervention of the plaintiff in aid of the primary duty or obligation the defendant had assumed. Such a general denial does not confess and avoid the cause of action, but presents the principal fact or transaction upon which an action for negligence is founded as evidence that the injury com*332plained of was not occasioned solely by the default of the defendant and without plaintiff having in any respect contributed to it.
Under these considerations, if, as was attempted to be shown, the plaintiffs had so assumed the control and management of the flow of water up to the defendant’s premises as to have relieved the defendant from vigilance and care as to the minor details of the water works on his premises, and from apprehension of any such accidental injury resulting from the water being left running, and an overflow being occasioned by a piece of segar falling into the urinal, plaintiffs’ omission of such duty constituted a fair subject for the consideration of the jury as an act of contributory negligence, and the evidence offered ought to have beenadmitted (Rudolphy v. Fuchs, 44 How. Pr. 155).
The plaintiffs were also allowed, under objection and exception, to introduce proof as to damages the goods had sustained, upon general and gross estimates by the witness, made without examination or knowledge of the kind or quality or of the particular extent of injury to the several articles in respect to and upon which such estimates were made. The plaintiff, Hervey Brown, was asked, Q. “ What was the amount of damaged goods ? Objected to; objection overruled; defendant excepts.” “ They amounted to $29,954 82. Q. Did you examine these goods, so that you are able to give an estimate of the amount of damages these goods suffered from the water ? A. I did not go into a minute examination of them as far as that goes, because the variety of goods was so great that the damage on some would be less, and others a great deal more; some of these goods were damaged fifty per cent, and some not ten. Q. What per cent, on the whole would be a fair amount on the whole to compensate for the loss ? Objected to; objection overruled, and defendant excepts. A. I should think near twenty-five per cent.” This was error. He was not shown competent to speak on the subject from any knowledge or examination of the goods, or the extent of injury each particular lot had sustained, so as to enable him to make a specification of the injuries or of each item constituting the gross sum or percentage on the whole as to which he was permitted to *333testify (Teerpenning v. Corn Ex. Ins. Co. 43 N. Y. 279; Wehle v. Haviland, 42 How. Pr. 399). He had disclosed his ignorance and inability to give legal evidence on the subject; and the answer to the last question could lead to but one result; to place himself in the stead of the jury, to assess in gross the plaintiffs’ damages (Decker v. Myers, 31 How. Pr. 378).
The plaintiffs were permitted to prove and recover, as part of their damages, the amount of injury to goods in their store belonging to a co-occupant, F. W. Smith, who did business there on his own account. They neither had possession nor any right of possession of these goods, and the charge that as to such goods defendant was bound specifically to set up such, want of title in plaintiffs, was erroneous.
There are some other errors in the numerous rulings of the judge to which exceptions were taken, as to which, any particular discussion is unnecessary, as the foregoing considerations are controlling in principle, and afford sufficient direction on a new trial, which should be ordered, with costs to abide the event.
Judgment reversed.
Present, Robinson, Larrehoee and J. F. Daly, JJ.