10, 1913, President Woodrow Wilson sent a signal from the White House by telegraph which triggered the explosion that destroyed the Gamboa Dike. This flooded the Culebra Cut, thereby joining the Atlantic and Pacific oceans via the Panama Canal. Alexandre La Valley (a floating crane built by Lobnitz & Company and launched in 1887) was the first self-propelled vessel to transit the canal from ocean to ocean. This vessel crossed the canal from the Atlantic in stages during construction, finally reaching the Pacific on January 7, 1914. SS Cristobal (a cargo and passenger ship built by Maryland Steel, and launched in 1902 as SS Tremont) on August 3, 1914, was the first ship to transit the canal from ocean to ocean. The construction of the canal was completed in 1914, 401 years after Panama was first crossed overland by Europeans by Vasco Núñez de Balboa's party of conquistadores. The United States spent almost $500 million (roughly equivalent to $ billion in ) to finish the project. This was by far the largest American engineering project to date. The canal was formally opened on August 15, 1914, with the passage of the cargo ship . The opening of the Panama Canal in 1914 caused a severe drop in traffic along Chilean ports due to shifts in maritime trade routes, despite the closure of the canal for nearly seven months after a land-slide in the Culebra Cut on September 18, 1915. The burgeoning sheep farming business in southern Patagonia suffered a significant setback by the change in trade routes, as did the economy of the Falkland Islands. Throughout this time, Ernest "Red" Hallen was hired by the Isthmian Canal Commission to document the progress of the work. In 1914 steam shovels from the Panama Canal were purchased and put to use in Chuquicamata copper mine of northern Chile. Later developments By the 1930s, water supply became an issue for the canal, prompting construction of the Madden Dam across the Chagres River above Gatun Lake. Completed in 1935, the dam created Madden Lake (later Alajuela Lake), which provides additional water storage for the canal. In 1939, construction began on a further major improvement: a new set of locks large enough to carry the larger warships that the United States was building at the time and planned to continue building. The work proceeded for several years, and significant excavation was carried out on the