Question: Liens. Karen and Gerald Baldwin owned property in Rapid City, South Dakota, which they leased to Wyoming Alaska Corp. (WACO) for use as a gas station and convenience store. The lease obligated the Baldwins to make repairs, but WACO was authorized to make necessary repairs. After seventeen years, the property was in such poor repair that customers were tripping over chunks of concrete in the parking lot and an underground gasoline storage tank was leaking. The store's manager hired Duffield Construction, Inc., to install a new tank and make other repairs. The Baldwins saw the new tank sitting on the property before the work began. When WACO paid only a small portion of the cost, Duffield filed a mechanic's lien and asked a South Dakota state court to foreclose on the property. The Baldwins disputed the lien, arguing that they did not request the work. What is the purpose of a mechanic's lien? Should property owners who do not contract for improvements be liable for the cost under such a lien? How might owners protect themselves against a lien for work that they do not request? Explain. [Duffield Construction, Inc. v. Baldwin, 679 N.W.2d 477 (S.Dak. 2004)]