## Facts

- Charles Lynn Williams worked in maintenance for entities associated with Don Stewart.
- The swimming pool on the premises was dirty, and Williams was instructed to clean it by unclogging the drain.
- Williams jumped into the pool to perform the task.
- Williams had a preexisting sinus infection; the jump’s mechanical force may have caused the infection to spread to his brain, resulting in severe injury.
- There was no evidence Stewart knew of Williams’s infection.
- There was no evidence the pool’s dirty condition (as opposed to the force of jumping into water) caused the infection to spread.
- Williams (through his guardian) and his mother sued Stewart and related entities for negligent pool maintenance.
- The trial court granted summary judgment to defendants; plaintiffs appealed.

## Issues

1. Whether permitting the pool to become dirty breached the duty to avoid unreasonable risks of harm to an employee directed to clean it.
2. Whether the injury suffered—spread of a preexisting sinus infection to the brain allegedly triggered by jumping into pool water—was a foreseeable harm within the scope of risks created by the alleged negligence.
3. Whether summary judgment was proper because no reasonable jury could find breach and liability on these facts.

## Decision

- The appellate court affirmed summary judgment for defendants.
- Defendants owed a general duty to avoid unreasonable risks of harm, but that duty was not breached because the harm was extraordinary and not reasonably foreseeable.
- Imposing liability for this type of idiosyncratic injury would effectively make pool owners insurers against rare medical reactions unrelated to the typical risks of a dirty pool.

## Legal Principles

- Negligence liability requires that the defendant’s conduct create an unreasonable risk of the type of harm that occurred; foreseeability limits the scope of what reasonable care requires.
- A defendant is not required to guard against events that are not reasonably anticipated, or are so unlikely that a reasonable person would commonly disregard the risk.
- When the plaintiff’s injury results from an unknown, unusual susceptibility and the defendant cannot identify who is at risk, the injury may fall outside the scope of foreseeable risks attributable to the defendant’s conduct.
- Courts may reject theories that would convert negligence principles into de facto strict liability for “freakish” injuries arising from ordinary activities.

## Conclusion

The court held that, even assuming negligent pool maintenance, the plaintiff’s brain injury from the mechanical effect of jumping into water acting on an unknown preexisting sinus infection was an extraordinary, unforeseeable harm outside the scope of risks a pool owner must reasonably prevent; summary judgment for defendants was proper.


Williams v. Stewart, 703 P.2d 546 (Ariz. Ct. App. 1985)