## Facts

- Lawrence D. McDougald drove behind a tractor-trailer on U.S. Highway 60 West in Bartow, Florida.
- Henry D. Perry drove the tractor-trailer, which C & S Chemical, Inc. leased from Ryder Truck Rentals, Inc.
- As the truck crossed railroad tracks, a 130-pound spare tire fell from an angled cradle underneath the trailer.
- The trailer’s rear wheels ran over the tire, causing it to bounce into the air and strike McDougald’s windshield.
- The spare tire was held in the cradle by its weight and a chain wrapped around it; the chain had one-inch links and was attached to the trailer with a nut and bolt rather than the original latch device.
- Perry testified he performed a pretrip inspection but did not check every chain link.
- After the incident, Perry observed the chain dragging and believed a link stretched and slipped from the nut; the chain was not available at trial.

## Issues

1. Whether res ipsa loquitur applies where a spare tire escapes from a moving tractor-trailer and strikes a following vehicle, permitting an inference of negligence without proof of a specific negligent act.

## Decision

- The Florida Supreme Court held res ipsa loquitur applied to the incident.
- The court quashed the Second District’s decision and approved the approach taken by the Fifth District in a similar detached-tire case.
- The case was remanded with directions to reinstate the trial court’s verdict for McDougald.

## Legal Principles

- Res ipsa loquitur is an evidentiary doctrine permitting, but not compelling, an inference of negligence when direct proof is unavailable.
- The doctrine applies when (1) the injury-causing instrumentality was under the defendant’s exclusive control, and (2) the event is of a type that ordinarily does not occur absent negligence.
- “Exclusive control” is satisfied when the defendant had responsibility for the instrumentality and its securing mechanism, even if deterioration or failure may have developed over time.
- The plaintiff need not eliminate all other possible causes with certainty; the presence of alternative explanations does not bar the inference if negligence is the more probable explanation based on common experience.
- The inference does not shift the burden of proof; it supplies circumstantial proof from which the jury may find negligence.

## Conclusion

The court concluded that a heavy spare tire ordinarily remains secured to a truck absent a failure of reasonable care by those responsible for the tire and its securing device, so the jury could infer negligence under res ipsa loquitur and the plaintiff’s verdict was reinstated.


McDougald v. Perry, 716 So. 2d 783 (Fla. 1998)