## Facts

- Joseph J. O’Sullivan, a social guest, visited the defendants’ home, which had an in-ground swimming pool with shallow and deep ends.
- The pool was approximately four feet deep at its shallowest point and eight feet at its deepest; the shallow end was level for about ten feet before gradually sloping toward the deep end.
- There were no depth markers or demarcations indicating where shallow water ended and deeper water began; a diving board was located at the deep end.
- The pool had no underwater lighting, and at night the bottom was not visible.
- O’Sullivan had previously used the pool during daylight, had seen others dive from the shallow end using a flat “racing dive,” and had himself dived from the deep-end diving board and once into the shallow end.
- Although he did not know the pool’s precise dimensions, O’Sullivan was aware generally where the shallow portion ended.
- On the night of the incident, O’Sullivan dove headfirst into the shallow end, struck the bottom, and suffered severe cervical injuries.
- He sued for negligence, alleging the defendants failed to post warnings or depth markers and failed to prevent shallow-end diving.
- The trial court granted summary judgment for the defendants, concluding shallow-end diving is an open and obvious danger and thus no duty was owed; the appellate court affirmed.

## Issues

1. Whether a residential landowner owes a duty to warn or protect a lawful visitor from the danger of diving into the shallow end of a swimming pool when that danger is open and obvious to a reasonable adult.
2. Whether Massachusetts’ comparative negligence statute abolishing assumption of risk eliminated or altered the open and obvious danger rule as a limitation on landowner duty.

## Decision

- The court affirmed summary judgment for the defendants.
- Diving headfirst into the shallow end of a swimming pool is an open and obvious danger as a matter of law on these facts.
- Because the risk was open and obvious, the defendants owed no duty to warn the plaintiff or to take additional measures to protect him from that risk.
- The abolition of assumption of risk did not abrogate the open and obvious danger rule, which remains a duty-based doctrine distinct from comparative fault.

## Legal Principles

- A landowner’s duty to lawful visitors to maintain property in reasonably safe condition ordinarily does not extend to dangers that are open and obvious to persons of average intelligence.
- The open and obvious danger rule limits duty as an objective matter; it is not merely a comparative negligence question for the jury in every case.
- Statutory abolition of assumption of risk does not eliminate duty-based limits on liability; a plaintiff must still establish that the defendant owed a duty, and no duty generally exists to warn of obvious hazards.
- Where no reasonable factfinder could conclude that a danger was not open and obvious, the court may resolve the duty question as a matter of law at summary judgment.

## Conclusion

The court held that the danger of diving headfirst into shallow water is open and obvious to a reasonable adult and therefore falls outside a residential landowner’s duty to warn or protect lawful visitors; the comparative negligence statute’s abolition of assumption of risk did not change this duty limitation, so summary judgment for the defendants was proper.


O'Sullivan v. Shaw, 726 N.E.2d 951 (Mass. 2000)