In an action to recover damages for personal injury, in which it was alleged that the defendants maintained a trailer negligently, so that two halts holding a “ strong back ” or crossbar were caused to 'break, thereby allowing it to fall and injure the. plaintiff, the defendants appeal from a judgment of the Supreme Court, Westchester County, entered February 6, 1962 after trial upon a jury's verdict in plaintiff’s favor against them. Judgment reversed on the law and on the facts, and a new trial ordered, with costs to the defendants to abide the event. Although the defendants were under a duty to discover all defects by more than just a visual inspection (fíe Maria v. Renee Operating Gorp., 282 App. Div. 221), in our opinion the finding of negligence against the defendants was contrary to the weight of the evidence. To satisfy the requirement of a prima facie ease, it was necessary that expert testimony be adduced to demonstrate the need for more, than a visual survey with respect to the bolts and the crossbar alleged to have been defective and to have been the cause of plaintiff’s injury, and to show that the defects, if any, arose from or were due to their metal structure. Ughetta, Acting P. J., ICleinfeld, Brennan and Hopkins, JJ., concur.