The proximate cause of an injury is that which, in a natural and continuous sequence, unbroken by any efficient intervening cause, produces an injury, and without which the injury would not have occurred.
The court accepted jurisdiction to examine the correctness of the appellate court's decision approving the trial court's instruction on proximate cause. The court reversed the lower courts' judgments as to all parties except for the owner. The court criticized the trial court's use of a jury instruction which stated that a proximate cause was one which was a substantial factor in causing the injury.
Was the appellate court’s decision in approving the trial court’s instruction on proximate cause correct?
The instant case illustrates the vice of the instruction as tending to mislead the jury. Here, the appellant was a passenger in an automobile. He brought suit against the driver of his vehicle, and both the driver and owner of the truck with which the automobile in which he was riding collided. One eye witness testified that the truck was traveling at between 45 and 55 miles an hour in a posted limit of 35 miles an hour and the driver admitted he had been traveling at 40 miles per hour prior to the accident. Investigation disclosed that the brakes on the truck were never applied. The law is, of course, that "there may be more than one proximate cause of an accident if each was an efficient cause without which the resulting injuries would not have occurred." The jury could have, under this instruction, found in favor of the City of Phoenix and its truck driver, on the theory that their negligence "contributed only slightly" and therefore was not a proximate cause.