## Facts

- Giant Powder Company operated a nitroglycerin-to-dynamite manufacturing plant on the shore of San Francisco Bay, including a nitroglycerin house and related buildings.
- An explosion began in the nitroglycerin house during processing and triggered successive explosions in nearby structures, resulting in a major detonation.
- The explosion destroyed or severely damaged neighboring property owned by the plaintiffs.
- All employees working at the time were killed, leaving no direct testimony establishing the specific cause of the initial explosion.
- Plaintiffs presented expert testimony that an explosion of this kind would not ordinarily occur if the plant and processes were properly managed and due care were used.
- It was undisputed that the explosion at defendant’s works caused the plaintiffs’ property damage.

## Issues

1. Whether, without direct evidence of the initiating cause, negligence could be inferred from the fact of an explosion occurring in a dangerous operation under the defendant’s exclusive control (res ipsa loquitur).
2. Whether an explosives manufacturer operating near other buildings is liable in damages for injury to those buildings caused by an explosion at its works.
3. Whether plaintiffs’ grant or consent to the defendant’s maintenance of the powder works nearby waived claims based on negligent operation.

## Decision

- The California Supreme Court affirmed the judgment for the plaintiffs and the denial of a new trial.
- The court held the evidence supported an inference of negligence because the instrumentalities were under defendant’s control and such explosions do not ordinarily occur if due care is used.
- The court held a powder manufacturer operating in proximity to other buildings is liable for damage to those buildings caused by an explosion at its works.
- The court rejected the argument that plaintiffs’ consent to the presence of the works waived claims for negligent operation.

## Legal Principles

- When damage results from an occurrence connected to an instrumentality under the defendant’s management, and the occurrence would not ordinarily happen if proper care were used, the plaintiff establishes a prima facie case permitting an inference of negligence (res ipsa loquitur).
- In such circumstances, the defendant bears the practical burden to offer an explanation consistent with due care to rebut the inference.
- One engaged in powder making in proximity to other buildings is liable in damages for injury to those buildings by explosion.
- Consent or a grant permitting maintenance of a lawful operation does not authorize negligent operation or waive claims arising from negligence.

## Conclusion

The court affirmed liability for blast damage, ruling that an unexplained explosion in an explosives plant under the operator’s exclusive control could support an inference of negligence, that explosives manufacturing near other buildings carries responsibility for explosion-related harm, and that neighboring owners’ consent to the plant’s presence does not excuse negligent operation.


Judson v. Giant Powder Co., 107 Cal. 549, 40 P. 1020 (Cal. 1895)