Pam and Dora own adjoining lots in the central portion of a city. Each of their lots had an office building. Dora decided to raze the existing building on her lot and to erect a building of greater height, and she received all governmental approvals required to pursue her project. There is no applicable statute or ordinance (other than those dealing with various approvals for zoning, building, etc.)"After Dora had torn down the existing building, she proceeded to excavate deeper. Dora used shoring that met all local, state, and federal safety regulations, and the shoring was placed in accordance with those standards. Pam notified Dora that cracks were developing in the building situated on Pam's lot. Dora took the view that any subsidence suffered by Pam was due to the weight of Pam's building, and correctly asserted that none would have occurred had Pam's soil been in its natural state. Dora continued to excavate. The building on Pam's lot suffered extensive damage, requiring the expenditure of $750,000 to remedy the defects. Which of the following is the best comment concerning Pam's action to recover damages from Dora?
Dora is liable, because she removed necessary support for Pam's lot.  Dora cannot be held liable simply upon proof that support was removed, but may be held liable if negligence is proved.  Once land is improved with a building, the owner cannot invoke the common law right of lateral support.  Dora's only obligation was to satisfy all local, state, and federal safety regulation