What are the elements of the doctrine of last clear chance?

The elements of the doctrine of last clear chance set out in Brandelius v. City & County of San Francisco, 47 Cal.2d 729 at page 743, 306 P.2d 432, at page 440, are as follows: 'The doctrine of last clear chance may be invoked if, and only if, the trier of the facts finds from the evidence: (1) that the plaintiff was in a position of danger and, by his own negligence, became unable to escape from such position by the use of ordinary care, either because it became physically impossible for him to escape or because he was totally unaware of the danger; (2) that defendant knew that plaintiff was in a position of danger and further knew, or in the exercise of ordinary care should have known, that plaintiff was unable to escape therefrom; and (3) that thereafter defendant had [216 Cal.App.2d 152] the last clear chance to avoid the accident by the exercise of ordinary care but failed to exercise such last clear chance, and the accident occurred as a proximate result of such failure.'