In Overton Memorial Hospital v. McGuire, 518 S.W.2d 528 (Tex. 1975) a patient fell out of a hospital bed and was injured. The Court held that negligently providing a bed without rails when the bed was being used to protect a patient that could not protect himself was "use" of tangible personal property that "caused" the plaintiff's injury. But the bed didn't do anything. It didn't expel the patient, nor did it permit someone to push the patient out of bed. Rather, the patient simply fell out of bed because there were no rails to hold him in bed.