## Facts

- The City of Rochester operated two water systems: a potable gravity-fed “Hemlock” system and a high-pressure “Holly” system used mainly for fire protection and canal lift bridges; the Holly water was sewage-contaminated.
- Near the Brown Street bridge, both systems connected to a common “Y” pipe supplying a hydraulic cylinder that raised and lowered the bridge; city employees controlled valves for each line.
- Because Holly pressure exceeded Hemlock pressure, a check valve on the Hemlock side was intended to prevent backflow of contaminated Holly water into the potable system.
- In the summer of 1910, contaminated Holly water entered the Hemlock system near Brown Street, and residents complained about the water’s taste and appearance; the city did not promptly correct the condition.
- Thomas E. Stubbs worked about one block from the Brown Street bridge and drank city water daily in that area.
- Stubbs remained in Rochester during the relevant period and drank only water obtained within the city.
- In September 1910, Stubbs contracted typhoid fever and alleged it resulted from the city’s negligent intermingling of the two systems and contamination of the potable supply.
- Medical testimony supported that Stubbs’s typhoid was caused by drinking contaminated water, and evidence indicated an unusual concentration of typhoid cases near the Brown Street area during the same period.

## Issues

1. In a negligence action where an illness could have multiple possible causes, must the plaintiff affirmatively disprove all other possible sources to reach the jury?
2. Was the plaintiff’s circumstantial, medical, and epidemiological proof sufficient to permit a reasonable inference, with reasonable certainty, that contaminated city water caused his typhoid fever wholly or in part?

## Decision

- The Court of Appeals reversed the nonsuit and granted a new trial.
- The court held the plaintiff was not required to negate every other conceivable cause of typhoid fever.
- The plaintiff’s evidence was sufficient for a jury to find, with reasonable certainty, that contaminated water attributable to the city’s conduct caused his illness wholly or in part.
- Because the record supported reasonable inferences rather than mere speculation, causation should have been decided by the jury.

## Legal Principles

- When multiple possible causes exist and the defendant is responsible for only some, the plaintiff must prove the injury was caused wholly or in part by a cause for which the defendant is responsible.
- The plaintiff need not exclude every other theoretical cause; it is enough to show facts permitting a finding with reasonable certainty that the defendant’s causal explanation is the direct and probable one.
- Circumstantial proof, expert medical opinion, and patterns consistent with localized exposure may support causation and justify submitting the case to the jury.
- Courts should not remove a case from the jury as “conjectural” when the evidence supports reasonable possibilities on which reasonable minds could differ.

## Conclusion

The court held that a plaintiff alleging disease from contaminated municipal water may reach the jury without disproving all other possible sources, so long as the evidence permits a reasonably certain inference that the defendant’s negligence probably caused the illness at least in part.


Stubbs v. City of Rochester, 226 N.Y. 516, 124 N.E. 137 (N.Y. 1919)