## Facts

- Robert Sullivan, an adult, rode as a guest passenger in a tractor-trailer driven by John W. Crabtree.
- Crabtree deviated from the direct route to stop at his home for supper; the crash occurred during this detour on U.S. Highway 41 while descending a mountain roadway with grades and curves.
- Conditions were midafternoon with clear, dry weather on a paved highway.
- After another truck passed, Crabtree’s vehicle suddenly swerved from the right to the left, left the roadway, overturned down a steep embankment, and fatally crushed Sullivan.
- Crabtree attributed the loss of control to possible loose gravel, broken pavement, or a brake problem, but ultimately could not identify the actual cause.

## Issues

1. Whether the circumstances of the truck’s unexplained departure from the roadway while under the driver’s control fall within res ipsa loquitur.
2. If res ipsa loquitur applies, whether it requires a directed verdict or shifts the burden of proof, or instead only permits the jury to infer negligence.

## Decision

- The court held that the circumstances supported applying res ipsa loquitur because the accident was the type that ordinarily does not occur without negligence and the instrumentality was under the defendant’s control.
- The court affirmed the defense verdict, holding that in Tennessee res ipsa loquitur creates a permissible inference of negligence for the jury, not a mandatory presumption and not a basis for directing a verdict on these facts.
- The court concluded that reasonable jurors could decline to infer negligence in light of the evidence and uncertainties about causation, so the verdict would not be disturbed on appeal.

## Legal Principles

- Res ipsa loquitur may apply in exceptional motor-vehicle cases where the occurrence itself supports an inference of negligence and the defendant had control of the instrumentality.
- In Tennessee, res ipsa loquitur generally functions as an evidentiary inference: it allows, but does not compel, a finding of negligence.
- The inference’s strength is for the trier of fact; the ultimate burden of persuasion remains with the plaintiff.
- A directed verdict based on res ipsa loquitur is improper unless the inference of negligence is so strong that all reasonable minds must reach the same conclusion.

## Conclusion

The court allowed the plaintiffs to rely on res ipsa loquitur to reach the jury but held that the doctrine did not require a negligence finding or shift the ultimate burden of proof; because the jury could reasonably reject the inference, the judgment for the driver was affirmed.


Sullivan v. Crabtree, 258 S.W.2d 782 (Tenn. Ct. App. 1953)