those states that a defendant's conduct was "wanton," "reckless" or "despicable", rather than merely negligent, can be significant because certain defenses, such as contributory negligence, are often unavailable when such conduct is the cause of the damages. Professional rescuer MacPherson v. Buick Motor Co., 217 N.Y. 382, 111 N.E. 1050 (1916) Judge Benjamin N. Cardozo which removed the requirement of privity of contract for duty in negligence actions. Martin v. Herzog, 228 N Y. 164, 126 N.E. 814 (1920) Tedla v. Ellman, 280 N.Y. 124, 19 N.E.2d 987, (1939) on negligence per se, or the violation of a duty under a statute Seong Sil Kim v. New York City Transit Authority, duty of care to a person who may have been attempting suicide. Breach of duty Breach is ordinarily established by showing that the defendant failed to exercise reasonable care. Some courts use the terms ordinary care or prudent care instead. Conduct is typically considered to be unreasonable when the disadvantages outweigh the advantages. Judge Learned Hand famously reduced this to algebraic form in United States v. Carroll Towing Co.: Where which means that if the burden of exercising more care is less than the probability of damage or harm multiplied by the severity of the expected loss, and a person fails to undertake the burden, he is not exercising reasonable care and is thus breaching his duty to do so (assuming he has one). In other words, the burden of prevention is less than the probability that the injury will occur multiplied by the gravity of the harm/injury. Under this formula, duty changes as circumstances change—if the cost of prevention increases, then the duty to prevent decreases; if the likelihood of damage or the severity of the potential damage increases, then duty to prevent increases. There are other ways of establishing breach, as well. United States v. Carroll Towing Co., 159 F.2d 169 (2d. Cir. 1947) Violation of statute This is also known as negligence per se. An incident would not have happened if there was not a breach. Breach can be shown in most jurisdictions if a defendant violates a statute that pertains to safety and the purpose of which is to prevent the result of the case. Note that this is an alternative way to show breach. A violation of statute will not have occurred in every case. Therefore, just because it cannot be shown does not