## Facts

- Gary O’Brien, a teenager, attended a social gathering at the Henry home, where an above-ground swimming pool was installed.
- The pool, manufactured by Muskin Corporation and sold through distributors/retailers, had a vinyl liner on the bottom and water depth of about three and one-half feet.
- O’Brien dove into the shallow pool; his hands slipped apart on the wet vinyl surface, his head struck the bottom, and he suffered severe spinal injuries.
- The pool displayed a “Do Not Dive” decal beneath the manufacturer’s logo in relatively small lettering.
- O’Brien sued in strict products liability, alleging (1) defective design because the vinyl liner was excessively slippery and dangerous in shallow water, and (2) inadequate warnings due to placement, size, and prominence.
- Experts disputed whether wet vinyl increased risk (plaintiff) or reduced risk by allowing arms to glide and protect the head (defense).

## Issues

1. Whether the design-defect claim should have been submitted to the jury under a risk–utility analysis.
2. Whether state-of-the-art evidence is relevant and admissible in a strict-liability design-defect case applying risk–utility balancing.
3. How warnings and the user’s conduct relate to strict liability and comparative negligence in this context.

## Decision

- The Supreme Court held the trial court erred by removing the design-defect issue from the jury.
- The Court held state-of-the-art evidence is relevant to risk–utility analysis and admissible in a strict-liability design-defect case.
- The Court modified and affirmed the intermediate appellate court’s disposition and remanded for a new trial in which the jury may consider design defect and warning adequacy with proper consideration of state-of-the-art evidence.

## Legal Principles

- A design-defect claim is evaluated by balancing product risks against product utility; the question is generally for the jury when it depends on factual weighing.
- “State of the art” (scientific and technological knowledge at the time of design) is a relevant factor in assessing feasibility and alternatives, but it is not a categorical defense to design-defect liability.
- A product may be found defectively designed even if it reflects the best technology then available; in an appropriate case, a jury may conclude the product’s risks so outweigh its utility that it should not be marketed in that form.
- Warning adequacy and the user’s ability to avoid danger are considerations within the overall defect analysis and may also bear on comparative negligence.

## Conclusion

The court required a new trial because the jury, not the judge, should decide whether the pool’s design was defective under a risk–utility test, and it clarified that state-of-the-art evidence is admissible and relevant but does not automatically bar design-defect liability.


O’Brien v. Muskin Corp., 94 N.J. 169, 463 A.2d 298 (N.J. 1983)