Eck | Tucker Arensberg PITTSBURGH – A landscaping firm contends that a pair of Pittsburgh homeowners, and not itself, are responsible for injuries that a local man suffered when an oak tree collapsed and fell on him. Steven L. Orebaugh and Jennifer Orebaugh first filed suit in the Allegheny County Court of Common Pleas on Jan. 28 versus Blystone Tree and Landscaping, Inc. All parties are of Pittsburgh. The suit said that David A. Mosey and Gertrude Van Kirk (not parties to the litigation) own a residential property in Pittsburgh, upon which several trees were located, including a large oak tree in the front yard, rooted near a driveway that had been excavated after the tree had been growing for many years.