## Facts

- A chain-reaction collision occurred at an intersection involving a line of five vehicles waiting to turn left.
- Justo Valle drove the second vehicle in line; Gloria Dinorah Díaz drove the third.
- A sixth vehicle struck the line from the rear, pushing Díaz’s car into Valle’s car.
- Valle sued Díaz and Díaz’s liability insurer, American International Insurance Company, seeking damages for personal injuries, vehicle damage, and mental suffering (including his wife’s).
- The trial court found Díaz negligent for stopping too close to Valle’s vehicle and treated that distance as the proximate cause of the impact, entering judgment for Valle with damages.

## Issues

1. In a chain-reaction collision, may a middle driver who is pushed forward by a rear impact be held liable to the driver ahead based on allegedly insufficient stopping distance under Puerto Rico Civil Code tort principles?
2. In Puerto Rico Civil Code tort cases, may courts use U.S. common-law doctrines as controlling rules, rather than as comparative authority?

## Decision

- The Supreme Court of Puerto Rico reversed the trial court’s judgment.
- The Court held the governing source of liability was Civil Code Article 1802, not traffic-law rules framed as dispositive standards for chain collisions.
- The Court concluded Díaz’s conduct (including her distance from Valle) was not the efficient, decisive cause of Valle’s damages; the rear vehicle’s impact was the determining cause of the chain reaction.
- The Court held that common-law doctrines cannot be used as binding rules to resolve Civil Code problems, though they may be consulted as comparative law.
- The Court overruled prior decisions to the extent they endorsed using common-law precepts to decide civil-law questions.

## Legal Principles

- Puerto Rico tort liability is governed in form and content by the civil-law system, principally Civil Code Article 1802.
- In chain-reaction automobile collisions, liability analysis proceeds under Article 1802, requiring fault and a causal nexus between the culpable act or omission and the damage.
- When multiple causes concur, causation requires identifying the “efficient” or “decisive” cause that, given the circumstances, determines the damage.
- An intervening third-party act may break causation only under limited conditions; not every subsequent act automatically severs causal responsibility.
- Common-law rules are not controlling in Puerto Rico Civil Code adjudication; they may be used only as persuasive, comparative material.

## Conclusion

The Supreme Court reversed a negligence judgment arising from a chain-reaction collision, holding that Article 1802 governed and that the decisive causal factor was the rear impact, not the middle driver’s stopping distance; it also reaffirmed that Puerto Rico courts must decide Civil Code tort problems using civil-law sources, treating common law solely as comparative authority.


Valle v. Am. Int’l Ins. Co., 108 D.P.R. 692 (P.R. 1979)