—Order, Supreme Court, New York County (Herman Cahn, J.), entered April 17, 1996, which, in a proceeding to recover for water damage under an all-risk insurance policy, denied plaintiff insured’s motion to reject the Referee’s report recommending denial of plaintiff’s claim, and granted defendant Liquidator’s cross motion to confirm the report, unanimously affirmed, with costs.
The Referee correctly held that the burden is on plaintiff to prove that the water damage it sustained was caused by a “fortuitous” event within the meaning of the policy, and not on *244defendant to prove the contrary (see, Avid Equities v Commerce & Indus. Ins. Co., 225 AD2d 446). The record supports the Referee’s finding that plaintiff failed to sustain this burden, plaintiffs attempt to show that pipe corrosion was the cause of the leak that caused the damage having been countered by defendant’s showing that pipe corrosion would have caused a slow leak detectable as it gradually grew larger and not the gushing of water that admittedly occurred, and that a valve at or near the source of the leak had been smashed with a blunt instrument. Plaintiffs only rejoinder to this evidence of external physical force, that the valve deformity was caused when plaintiffs plumber struck the valve with a chisel while making repairs, was rebutted, and at best raised an issue of credibility for the Referee (see, Freedman v Freedman, 211 AD2d 580). We have considered plaintiffs other arguments and find them to be unavailing. Concur — Lerner, P. J., Wallaeh, Tom and Andrias, JJ.