(dissenting). The majority holds that there need not be a causal connection between a com-pensable injury and an employee's inability to work when the employee seeks disability benefits based on lost earning capacity. The majority thus sanctions an award of full lost-earning-capacity disability benefits to an employee who, for all intents and purposes, is totally disabled from a non-compensable illness.
Jan E. Niecko originally sought permanent total disability benefits based on both his September 20,1985, back injury and his serious lung disease. He later withdrew the lung-disease claim. The Labor and Industry Review Commission determined that Niecko's back injury caused him permanent partial disability equal to fifteen percent of the body as a whole, but awarded him one-hundred percent permanent total disability even though it recognized that had Niecko "not sustained the work injury [to his back] on September 20, 1985, he would have shortly thereafter been required to cease working due [to] his lung condition." The crux of the Commission's rationale, and the majority's affirmance, is that Niecko "had not ceased working at the time" of his September 20, 1985, back injury even though he was essentially totally disabled at that time as a result of his lung disease.
The Commission, the trial court, and the majority ignore the statutory command that the compensable *257injury must be the cause of the disability that underlies an award.1 See sec. 102.03(l)(a) and (e), Stats., ("Liability under this chapter shall exist against an employer only where . . . the employe [sic] sustains an injury" and where "the accident or disease causing injury arises out of his employment.'1). Cf. sec. 102.175, Stats., (Liability for two or more compensable injuries must be "apportioned according to the proof of the relative contribution to disability resulting from the injury.1'). See also Wis. Adm. Code, sec. Ind. 80.34(1) ("Any departmental determinations as to the loss of earning capacity for injuries arising under s. 102.44(2) and (3), Stats., shall take into account the effect of the injured employe's [sic] permanent physical and mental limitations resulting from, the injury upon present and potential earnings . . .." [Emphasis added]). Since the Commission disregarded its mandate, it acted in "excess of its powers." See sec. 102.23(l)(e)l, Stats. The award should be set aside, and the matter remanded to the Commission for a determination of the extent to which, if any, Niecko's back injury, standing alone, affected his earning capacity.
At the September 7, 1987, hearing on the back claim, Niecko testified that he retired because of a favorable disability ruling by the Social Security Administration of the United States Department of Health and Human Services, which awarded him disability benefits because of his lung disease but not his back problem.