## Facts

- Cynthia Ann Holtz drove north on 24th Street in Phoenix and stopped at a red light at Thomas Road in the left lane; James E. Holder stopped to her right.
- North of the intersection, construction narrowed the roadway so the right lane was partially blocked by dirt piles, leaving insufficient room for both vehicles to proceed side by side.
- When the light turned green, Holtz and Holder proceeded forward and collided as the road narrowed.
- The collision pushed Holtz’s vehicle across the center line into a stopped southbound pickup truck, leaving her car positioned crosswise in the lane.
- Approximately five to ten minutes later, a Carnation Company milk truck turned north onto 24th Street, attempted to pass on the right by driving over a dirt mound, and struck Holtz’s stopped car in a manner not clearly established by the evidence.
- Medical testimony stated it was impossible to determine which injuries were attributable to the first collision versus the later truck impact.

## Issues

1. When independent, successive negligent acts may have contributed to a single, indivisible injury that cannot be apportioned, must the plaintiff fail for inability to allocate damages between defendants?
2. Did the trial court err by instructing the jury that it could not find for the plaintiff unless it could determine which defendant caused which injuries, and by refusing an instruction allowing joint and several liability where apportionment is impossible?

## Decision

- The Arizona Supreme Court reversed the defense judgment and remanded for a new trial.
- The court held that where independent, successive torts produce a single, indivisible injury and apportionment is impossible, the plaintiff is not required to apportion harm among tortfeasors.
- The court held the jury instruction requiring apportionment as a condition of liability misstated the law and improperly barred recovery.
- The court concluded the requested instruction permitting joint and several liability in the event of non-apportionable harm should have been given.

## Legal Principles

- When separate negligent acts combine to cause an indivisible injury that cannot be reasonably divided, each negligent actor may be held jointly and severally liable for the entire harm.
- A plaintiff need not prove the precise portion of an indivisible injury caused by each defendant when competent evidence shows apportionment is not feasible.
- A jury instruction that requires a plaintiff to allocate damages among multiple negligent defendants as a prerequisite to recovery is erroneous when the harm is indivisible.

## Conclusion

The court ordered a new trial because the jury was wrongly instructed to deny recovery unless it could assign specific injuries to each defendant; in cases of indivisible, non-apportionable harm caused by independent successive negligence, liability may be imposed jointly and severally on each negligent defendant.


Holtz v. Holder, 101 Ariz. 247, 418 P.2d 584 (Ariz. 1966)