Engineer A is hired by Client B to conduct a building investigation to determine the origin and cause of a fire resulting in financial loss. During the investigation, Engineer A, who was also a structural engineer, observes that the building is structurally unstable. Engineer A performs a preliminary investigation of the building and after speaking with Client B, concludes that there were recent structural changes made to the building that may have caused the roof to sag and the walls to lean outward due to insufficient lateral restraint. Engineer A also learns that following construction modifications, the building was issued a certificate of occupancy by a county building official. Although not imminent, collapse of the building is a danger, Engineer A believes. Engineer A immediately advises Client B and calls the county building official. The county building official did not return Engineer A\'s phone call. Engineer A also recommended to the owners to brace the building to prevent its collapse.

Question: What are Engineer A\'s ethical obligations under the circumstances?