In a consolidated action to recover damages, inter alia, for personal injuries and wrongful death, the third-party defendant appeals from an order of the Supreme Court, Kings County (Jackson, J.), dated February 8, 1996, which denied its motion pursuant to CPLR 3216 to dismiss the complaint and all claims, including the third-party complaint, asserted against it, and granted the plaintiffs’ cross motion to extend their time to file a note of issue.
Ordered that the order is reversed, on the law, with costs, the motion is granted, the cross motion is denied, the complaint is dismissed, and all other claims, including the third-party complaint, insofar as asserted against the third-party defendant-appellant are dismissed.
To avoid being held in default, a party served with a 90-day notice pursuant to CPLR 3216 must either comply with the notice by filing a note of issue, or moving, before the default date, to vacate the notice or to extend the 90-day period (see, Shu Chaing Chan v Fendt, 187 AD2d 574; Kirkland v Community Hosp., 187 AD2d 566). Having failed to pursue either of the foregoing options, the plaintiffs were obligated to demonstrate both a justifiable excuse for the failure to comply with the 90-day notice and the existence of a meritorious cause of action (see, CPLR 3216 [e]; Shu Chaing Chan v Fendt, supra; M.P.S. Mktg. Servs. v Champion Intl. Corp., 176 AD2d 250). The plaintiffs have failed to demonstrate the existence of a meritorious cause of action since the affidavit of merit submitted by the plaintiffs merely stated in conclusory fashion that the defendants were negligent. Accordingly, dismissal was warranted. Miller, J. P., Thompson, Joy and Luciano, JJ., concur.