In Marker v. Department of Transportation, 677 A.2d 345 (Pa. Cmwlth.), appeal denied, 546 Pa. 671, 685 A.2d 549 (1996), Mrs. Marker was driving on a state highway when a tree fell on her car and caused her death. Mr. Marker filed an action against DOT asserting negligent maintenance of the highway and adjacent property, and the jury rendered a verdict in his favor. The trial court upheld the verdict, rejecting as immaterial DOT's contention that the real estate from which the tree grew was outside DOT's right-of-way. However, relying on Snyder, this court stated: Contrary to the trial court's opinion ... the characterization of the real estate from which a dangerous condition derives or originates from is material. If the real estate in question from which the dangerous condition derives, originates from or has as its source is not Commonwealth realty, then the Commonwealth cannot be held liable under the real estate exception to sovereign immunity. Marker, 677 A.2d at 348. Because Mr. Marker failed to establish that the tree which fell and killed Mrs. Marker was located on Commonwealth realty, this court reversed and remanded for a judgment in favor of DOT. In doing so, we refused to evaluate DOT's duties imposed by its maintenance manuals to inspect property adjacent to highways for potential harm to users of the Commonwealth highways.