When there are multiple possible causes of the plaintiff’s harm—only some of which the defendant is responsible for—should the plaintiff be required to disprove all other possible causes in order to prevail? For several months, the defendant waterworks failed to keep sewage-infested water from mingling with the city’s potable water. During this period, the plaintiff drank contaminated tap water and contracted typhoid fever. The plaintiff sued the city on the theory that the polluted water was the cause of his illness. However, typhoid fever was known to have at least eight different causes, many of which are independent from contaminated drinking water. At trial, the plaintiff produced much evidence that supported contaminated drinking water as the likely cause of his affliction. However, he does not provide evidence which eliminates all the other possible causes.