Ferdinand de Lesseps' Panama Canal project fell into bankruptcy after seven years and spending a billion francs with little progress, as they were unable to control a disease epidemic or address the region's unsuitable landscape for a sea-level canal. The United States later took over the project, first focusing on eliminating mosquitos to curb yellow fever and malaria, then entrusting the army to finish the canal using a lock system like the abandoned French plan, constructing a dam to create Lake Gatun for water supplies and allowing ships to cross the isthmus at a higher elevation.