## Facts

- Chester W. Skinner operated a small business cleaning and finishing metal parts.
- Skinner designed and built a homemade tumbling machine consisting of a metal drum, frame, and electric motor that rotated the drum to wash parts and, when reversed, ejected finished parts.
- The machine used a Square D drum-type switch to control power to the motor; wires from the switch ended in alligator clips.
- To reverse rotation, the operator would turn the switch off, disconnect two clips from the motor, and swap them.
- In February 1986, while working alone, Skinner was found holding an alligator clip in each hand while current flowed through him; he removed one clip, flipped the switch, collapsed, and died.
- Plaintiffs alleged the switch was defective because it did not always clearly indicate whether it was in the “on” or “off” position.
- Plaintiffs theorized Skinner mistakenly believed the machine was off because the switch position was ambiguous and the drum was not moving and the machine was not making noise (the clips were not connected to the motor), even though the clips were energized.
- Plaintiffs asserted products-liability claims including defective design/condition of the switch, failure to insulate the switch handle, and failure to warn.
- The trial court granted summary disposition for defendant under MCR 2.116(C)(10), finding insufficient evidence of cause-in-fact and dismissing the insulation and warning claims; the Court of Appeals affirmed.

## Issues

1. Whether plaintiffs produced evidence creating a genuine issue of material fact that an alleged defect in the switch was a but-for cause of Skinner’s death, sufficient to defeat summary disposition under MCR 2.116(C)(10).
2. Whether dismissal of the failure-to-insulate and failure-to-warn claims was proper on the record.

## Decision

- The Michigan Supreme Court affirmed.
- The Court held plaintiffs did not present evidence from which reasonable minds could infer that the alleged switch defect caused the death.
- The Court concluded plaintiffs’ causation theory depended on conjecture and an unsupported chain of inferences rather than facts permitting a reasonable inference of but-for causation.
- The Court also upheld dismissal of the failure-to-insulate and failure-to-warn claims.

## Legal Principles

- In products-liability cases, a plaintiff must present admissible evidence supporting a reasonable inference that the alleged defect was a cause in fact (but-for cause) of the injury.
- Circumstantial evidence may prove causation, but it must support a conclusion that causation is probable; evidence showing only that the theory is possible, or equally consistent with competing explanations, is insufficient.
- An explanation consistent with known facts but not reasonably deducible from them is impermissible conjecture and cannot create a triable issue.
- On a motion under MCR 2.116(C)(10), once the movant supports the motion, the nonmovant must go beyond pleadings and produce evidence showing a genuine issue of material fact on elements for which it bears the burden of proof.
- Summary disposition is appropriate when reasonable minds could not differ because a required element, such as causation, cannot be established without speculation.

## Conclusion

The court affirmed summary disposition because plaintiffs’ circumstantial proof did not permit a reasonable jury to find, more likely than not, that an ambiguous switch position caused the decedent to grasp energized clips; the causal link rested on speculation, and the related insulation and warning theories likewise failed on the record.


Skinner v. Square D Co., 516 N.W.2d 475 (Mich. 1994)