Ralph Hanke made a terrible mistake on Jan. 8, 1995, while resurfacing an ice rink in Edmonton, Alberta. On that day he filled the gas tank of his Zamboni-like machine with hot water. The gas tank on the machine, which was made by Resurfice Corp., is next to the water tank. The hot water caused the gas in the tank to evaporate and drift toward an overhead heater. The vapor ignited in a massive explosion, scorching 90 percent of Hanke’s body.

Soon after Hanke filed a negligence claim against Resurfice. Relying on the “but for” test to determine causation, the trial court denied his claim. Under the “but for” test a plaintiff must prove the injury wouldn’t have occurred but for the negligent conduct of the defendant.