## Facts

- During a severe heat wave in July 1966, an electric utility’s generating capacity was heavily strained, prompting an emergency load-reduction plan.
- The utility implemented phased measures culminating in involuntary, rolling curtailments to specified geographic areas across the St. Louis metropolitan region.
- A grocery chain operated supermarkets in an area subjected to the rolling curtailments.
- Electric service to the stores was interrupted without advance warning to the grocery chain.
- The grocery chain claimed the unannounced interruption caused spoilage of refrigerated and frozen inventory and sought damages, framing the negligence as failure to warn so it could mitigate loss.
- The parties’ service relationship was governed by filed tariffs and service regulations that included provisions limiting liability for service interruptions.
- A jury awarded the grocery chain $5,800.
- The trial court set aside the verdict and entered judgment for the utility on the ground there was no legal basis for liability; alternatively, it ordered a new trial based on an erroneous verdict-directing instruction.
- The grocery chain appealed.

## Issues

1. Whether an electric utility owes a common-law duty to exercise reasonable care to warn a customer of a foreseeable, nonroutine service curtailment when warning is practicable.
2. Whether tariff-based limitations of liability for service interruptions bar a tort claim premised on negligent failure to give notice of an impending curtailment.
3. Whether failure to warn can constitute a proximate cause of a customer’s economic loss from spoilage under emergency rolling-curtailment conditions.
4. Whether the plaintiff’s verdict-directing instruction properly submitted the required negligence and causation elements to the jury.

## Decision

- The appellate court held the utility could owe a common-law duty of reasonable care to provide warning of impending curtailment when practicable, given foreseeability of harm to a supermarket dependent on continuous refrigeration.
- The court rejected the view that tariff liability limitations automatically barred a tort claim based on failure to warn, distinguishing that omission from damages attributed solely to an interruption.
- The court reversed the judgment entered for the utility notwithstanding the verdict.
- The court affirmed the trial court’s alternative ruling that the plaintiff’s verdict-directing instruction was erroneous.
- The case was remanded for a new trial rather than reinstatement of the jury’s award.

## Legal Principles

- A public utility is not an insurer of uninterrupted service, but it must exercise reasonable care under the circumstances.
- When a utility knows or should know that a customer’s operations will foreseeably suffer substantial harm from an unannounced interruption, the utility may have a tort duty to provide practicable notice of a planned or foreseeable curtailment.
- Tariff provisions limiting liability for service interruptions do not necessarily preclude tort liability for a separate negligent act or omission, such as failure to warn, as distinguished from liability for the outage itself.
- Negligence submissions must require the jury to find the ultimate facts constituting breach and causation; a verdict-directing instruction that fails to do so warrants a new trial.

## Conclusion

The court recognized a potential tort duty for an electric utility to give practicable warning of an impending emergency curtailment where harm to a dependent customer is foreseeable, held tariff limits did not categorically bar a failure-to-warn claim, and ordered a new trial because the plaintiff’s verdict-directing instruction inadequately submitted negligence and causation.


National Food Stores, Inc. v. Union Elec. Co., 494 S.W.2d 379 (Mo. Ct. App. 1973)