The various conditions of which safe-place law takes cognizance have been classified as (A) structural defects, (B) unsafe conditions associated with the structure, and (C) unsafe conditions unassociated with the structure. [0] As heretofore mentioned, an owner of a public building is concerned with only the first two categories; an employer and an owner of a place of employment are concerned with all three.

0. Barry, v. Employers Mutual Casualty Company, 2000 WI App 168 ¶ 6, 238 Wis. 2d 125, 131, 617 N.W. 2d 493, 496 (Ct. App. 2000), citing this treatise.