In City of Auburn v. Desgrosseilliers, 578 A.2d 712 (Me. 1990), the plaintiffs met with a city official to discuss operating a multi-business operation in Auburn consisting of a gift shop, photographic studio, landscaping business and tree nursery. Id. at 712. A city official helped the Plaintiffs draw up a petition to request a change in the zoning district from the Urban Residence zone to the General Business zone in order for Plaintiffs to establish their business at the proposed site. The Plaintiffs submitted their plan to the Planning Board, again disclosing that they planned to operate, among other things, a landscaping business and tree nursery. Id. at 713. The zoning change was approved by the Planning Board and City Council. Neither the town official, nor the Planning Board and City Council informed the Plaintiffs that landscaping services and tree nurseries were not permitted in the General Business zone. The Plaintiffs began conducting their multi-business operation in 1985 and during the following three years sought and received permits to display signs on their property that showed that the Plaintiffs operated a nursery and landscaping business. Id. at 714-15. The City did not give them any indication that their business activities were illegal until 1987, and did not commence an enforcement action until 1988. Id. at 713, 715. In reaching the conclusion that the City could be equitably estopped from enforcing the ordinance, the Law Court stated that "the City misled the Desgrosseilliers into investing in their landscaping service and nursery business in 1985, failed to give them any indication that their business activities were illegal until 1987, and did not commence an enforcement action until 1988." Id. at 715.