Order, Supreme Court, New York County (Robert Lippmann, J.), entered July 19, 2002, which, to the extent appealed from as limited by the brief, denied plaintiff’s motion to amend the pleadings to add a cause of action for wrongful death, unanimously affirmed, without costs.
*142While leave to amend a pleading is freely given (CPLR 3025 [b]), the court properly exercised its discretion in denying such leave since plaintiff failed to support her motion with “competent medical proof of the causal connection between the [accident] and the death of the original plaintiff’ (McGuire v Small, 129 AD2d 429 [1987]). Plaintiff’s decedent sustained.injuries when he fell from a ladder. He died approximately 21l% years later, and esophageal cancer was listed as the sole cause of his death. Plaintiffs conclusory medical affidavit was insufficient to establish a causal connection between the decedent’s cancer and his injuries, or to establish that the injuries played a role in hastening his death. Although plaintiffs expert’s affidavit set forth an alleged chain of events, it explained the cause-effect relationships between the links of the chain in conclusory terms and failed to indicate what medical records were reviewed. Furthermore, the expert did not set forth his credentials.
In addition, defendants would be prejudiced by the addition of the wrongful death claim because they had not been previously made aware of any potential cancer-related claim by way of a bill of particulars or otherwise and because, under the circumstances, they were unable to conduct any meaningful investigation in order to prepare adequate defenses. Concur—Nardelli, J.P., Mazzarelli, Andrias, Sullivan and Lerner, JJ.