Fein and Alexander, JJ.,dissent in a memorandum by Alexander, J., as follows: I would affirm the judgment entered in favor of the plaintiff, Jewish Board of Guardians, against the defendants Grumman and Biuso, as well as the indemnification judgment in favor of third-party plaintiff Biuso against third-party defendant Auriga. I would also affirm the order denying the motion of the defendant Grumman for leave to amend its answer. While, as the majority observes, an agreed-upon division of function and duty among the parties appears from the contract documents, the trial record makes it clear that under the circumstances that prevailed at the job sites, the parties by their conduct, demonstrated that they did not intend to and in fact did not adhere strictly to that division of function.and duty set forth in the contract *468documents. Moreover, the evidence at trial demonstrates that the over-all circumstances surrounding this construction site, as recognized by the parties, imposed obligations and duties beyond those specified by the literal language of the contracts. Initially, it should be observed that the trial evidence adequately demonstrated, and the jury apparently found, that the specifications prepared by Biuso were inadequate in that they were insufficient in their detail as to the responsibilities that should be imposed upon Auriga, the contractor and Grumman, the manufacturer of the modular units, to insure that the owner Jewish Board of Guardians received that which it was to receive as the completed construction project. Additionally, Biuso was delinquent in the discharge of his supervisory responsibilities. He was present at the construction site on the day that the last of the modular units was delivered. He was charged with the responsibility of determining that the temporary protection placed on those modular units was sufficient to accomplish its purpose and he should have known that the Visqueen sheeting placed over the modular units, anchored only by the one by twos, was insufficient, to afford adequate protection. Thus, he should have at least called the fact of this inadequacy to the attention of Auriga the contractor, Grumman the builder, or both. This he failed to do and that failure was sufficient to cast him in damages. Moreover, there was extensive, unrebutted trial testimony that because the specifications prepared by Biuso called for the field application of the permanent roof, more careful provisions were required to be made for the protection of the modular units on site prior to the application of the permanent roof. The jury may well have found that the specifications were deficient in this regard, and therefore that Biuso was negligent. Indeed, the plaintiff’s expert, Ehrenkrantz, testified that the specifications prepared by Biuso were only “minimal”. Although the contract specifications provided that the contractor, Auriga, was obligated to provide and install all necessary temporary protection to prevent the intrusion of the elements, the specifications also provided that Grumman had the responsibility to caulk and weatherproof the units. As the manufacturer of and the party having greater knowledge and expertise in the installation of these modular units, which apparently involved a relatively innovative construction concept, Grumman knew or should have known that the temporary alignment of the units, as they were placed on the site, awaiting the installation of the permanent roof, made them particularly vulnerable to damage from the elements, especially at that time of year (November — December) when the weather was extremely harsh. The Grumman executive whose deposition was received at trial, testified that he and Biuso and a representative from Auriga discussed the schedule for delivery of the modular units. It was agreed among them that as quickly as the units were delivered, they would be off-loaded and set on foundations and thereafter immediately joined and weatherproofed with the permanent roof so that the elements would not affect the job. The last of the modular units was delivered and off-loaded on a Friday afternoon; at a time when it was clear that the modular units would be exposed over the weekend, since no additional work was to be done until the following Monday. Under these circumstances, applying the “reasonable man” test to Grumman’s conduct, the jury may well have found that Grumman failed in its responsibilities by failing to make sure that Auriga was fully and properly instructed as to those steps necessary not only to properly join the modular units, but also to protect them during the interim, pending their permanent joinder. Grumman’s contract imposed upon it the duty to instruct Auriga as to the permanent joining of the modulars. This duty carried with it the obligation to give proper instructions for the protection of the modulars prior to joining them together. When considered with the evidence that the modular units Grumman delivered did not meet the specifi*469cations, as they were required to do, in that one ply of the felt covering for the temporary roof was missing and that the plywood sheeting attached to the felt was not adequately cut back, thereby preventing a flush joinder of the adjacent units, there was an ample basis for finding Grumman negligent. Indeed, contrary to the conclusion reached by the majority, there was evidence before the jury that the failure of Grumman to properly “cut back” the plywood prevented the proper application of the Visqueen used to protect the modular units from the elements. In these circumstances, this court should not disturb the jury’s factual determinations based upon contractual interpretations, particularly where the evidence demonstrates that the parties themselves accepted responsibilities beyond those imposed by the literal language of the contracts. The parties reserved questions of indemnification on the various cross claims to the court and Biuso’s claim for indemnification against Auriga was allowed, but Auriga was denied indemnification from Grumman on its claim over. This determination was in accordance with the indemnification provisions of the respective contracts and should not be disturbed. Auriga was obligated under paragraph 4.18.1 of the general conditions of the contract: “[t]o indemnify and hold harmless the owner and the Architect * * * from and against all claims, damages, losses and expenses * * * arising out of or resulting from the performance of the work * * * (2) caused in whole or in part by any negligent act or omission of the contractor, any subcontractor * * * regardless of whether or not it is caused in part by a party indemnified hereunder.” (Emphasis added.) Thus Biuso was entitled to be indemnified for its 10% share of the plaintiff’s recovery, even though that liability resulted from Biuso’s own negligence (Levine v Shell Oil Co., 28 NY2d 205; Emery v Depot Constr. Co., 53 NY2d 971). As to Auriga’s entitlement to indemnification from Grumman however, a totally different clause and circumstance is involved. Grumman, as subcontractor assumed “entire responsibility and liability for any and all damages or injury of any kind arising out of its negligence” (and agreed) to “indemnify and save harmless * * * Auriga Building Corporation * * * from and against any and all loss, expense, damage or injury that * * * Auriga Building Corporation may sustain as a result of any such claim” (emphasis added). The court correctly found this language to be clear and unambiguous and that it required Grumman to assume responsibility and liability for damage “arising out of its negligence.” Since Auriga’s “loss, expense, damage or injury” was sustained by reason of its contractual obligation to indemnify Biuso and not by reason of Grumman’s negligence, Auriga had no valid claim over against Grumman under the language of the indemnity agreement quoted above. Finally, the court did not abuse its discretion in denying Grumman’s application, made on the eve of trial, to amend its answer. While leave to amend pleadings should be freely given (CPLR 3025, subd [b]) “fljeave to amend rests in the sound discretion of the court (Harriss v Tams, 258 NY 229, 240)” (Birdsall v City of New York, 60 AD2d 522). Here, more than four years had elapsed since Grumman had filed its initial answer, extensive discovery had been conducted and the case was set for trial in August, 1980. This motion to amend was not made until September, 1981, after a trial date of September 15 had been set. Trial Term did not find Grumman’s reasons for the extended delay persuasive, and its decision should not be disturbed (cf. Williams v New York Univ. Hosp., 88 AD2d 540).