## Facts

- Davis M. Swiney was driving north on U.S. Highway 11-W in Grainger County, Tennessee, when he encountered a tractor-trailer driven by Charles Wayne Wilson and leased to Malone Freight Lines.
- The truck’s dual tandem wheel assembly malfunctioned: one wheel detached and was avoided; shortly afterward a second wheel detached and struck the front of Swiney’s car.
- Swiney sustained personal injuries and property damage.
- Evidence indicated the wheel detachment resulted from sheared lug bolts (or lug nuts), allowing the wheels to disengage.
- Defendants presented proof of due care, including a company inspection four days earlier, Wilson’s same-day wheel check using a “tire billy,” and a same-day inspection by Tennessee Public Service Commission personnel at the state line.

## Issues

1. Whether res ipsa loquitur may apply when a wheel detaches from a moving vehicle and causes injury.
2. If res ipsa loquitur applies, whether defendants’ inspection and due-care evidence required a directed verdict as a matter of law.

## Decision

- The appellate court affirmed the judgment for the plaintiffs.
- Res ipsa loquitur was properly submitted to the jury because the occurrence was the type that ordinarily does not happen absent negligence, and the instrumentality was within defendants’ control.
- Defendants’ inspection evidence did not conclusively negate negligence; it presented a jury question rather than requiring a directed verdict.

## Legal Principles

- Res ipsa loquitur permits, but does not compel, an inference of negligence when the instrumentality causing injury was under the defendant’s control and the event ordinarily does not occur without negligence.
- In a wheel-detachment incident, the unusual nature of the occurrence can support the res ipsa inference under appropriate circumstances.
- Res ipsa loquitur does not shift the ultimate burden of proof; the defendant may offer an explanation, and the factfinder determines whether negligence is shown by a preponderance of the evidence.
- Evidence of inspections and asserted due care generally affects the weight of the inference and will not defeat res ipsa as a matter of law unless it so conclusively rebuts negligence that reasonable minds could not differ.

## Conclusion

The court held that a wheel detaching from a moving tractor-trailer can support a res ipsa loquitur inference of negligence and that evidence of inspections and due care, without conclusively disproving negligence, leaves liability for the jury to decide.


Swiney v. Malone Freight Lines, 545 S.W.2d 112 (Tenn. Ct. App. 1976)