In the end, the engineers and workers minimized the mosquito threat; moved, rebuilt and expanded the Panama Railroad; excavated over 200,000,000 cu yd (152,910,972 m3) of earth; built the world's largest (then) dam and a lake; poured about 2,000,000 cu yd (1,529,110 m3) of concrete creating a spillway at Gatun Lake to control its height; and formed three sets of double 110 feet (34 m) by 1,000 feet (300 m) ship's locks, then the largest concrete pour in the world. This was supported by an extensive buildup of U.S.-built, then-modern, heavy duty excavation and construction equipment; and one of the world's earliest and most extensive electrical systems, used to power and control the flow of water into the locks and spillway. The U.S. spent almost $375,000,000 (roughly equivalent to $8,600,000,000 now), including $12,000,000 to build facilities used to guard the canal, to finish the project. This was, by far, the largest American engineering project of that or any previous era. The canal was formally opened on August 15, 1914 with the passage of the cargo ship SS Ancon. Coincidentally, this was also the same month that fighting in World War I (the Great War) began in Europe. The advances in hygiene resulted in a relatively low death toll during the American construction; still, about 5,600 workers died during this period (1904–1914). This brought the total death toll for the construction of the canal to around 27,500.