In a negligence action to recover damages for- personal injuries and loss of services, etc., plaintiffs appeal from a judgment of the Supreme Court, Suffolk County, entered July 27, 1972, in favor of defendant, upon a jury verdict, after á trial on the issue of liability only. Judgment reversed, on the law, and new. trial granted, with costs to abide the event. The appe.al did not present questions of fact. Despite the absence of any evidence which could conceivably support a finding that plaintiffs were guilty of contributory negligence, and over objection by their counsel, the trial court charged that doctrine. In the light of the evidence, this was error (Willis v. Young Men’s Christian Assn, of Amsterdam,, 28 N Y 2d 375). It was also error to bar plaintiffs’ expert ■from testifying to what his opinion was with respect to the cause of the fall of - the duet here in issue. Rabin, P. J., Hopkins, Martuscello, Latham and Shapiro, JJ., concur.