— Order unanimously reversed on the law without costs and defendant hospital’s motion granted. Memorandum: The court erred in granting plaintiffs’ motion to vacate or amend a prior conditional order of preclusion requiring plaintiffs to serve a bill of particulars and medical authorizations upon defendant within 30 days. Following entry of the prior order, plaintiffs failed to comply with it or request an extension, prompting defendant to move to enforce the order of preclusion and dismiss the complaint. Instead, the court granted plaintiffs’ cross motion to permit them to serve the bill of particulars within 20 days of determination of the motions.
Plaintiffs failed to show a reasonable excuse for the lengthy delay in serving the bill of particulars. Moreover, plaintiffs failed to submit an affidavit of merit attested to by a person with knowledge of the facts. Thus, plaintiffs’ motion to be excused of their default should have been denied and defen*905dant’s motion to dismiss granted (see, La Buda v Brookhaven Mem. Hosp. Med. Center, 98 AD2d 711, affd 62 NY2d 1014). (Appeal from order of Supreme Court, Erie County, Gossel, J. —dismiss action.) Present — Doerr, J. P., Denman, Boomer, Lawton and Davis, JJ.