The conclusion of this two-part special presents the story of the building of the Canal. The lessons learned from de Lesseps' failure led the United States to develop a lock canal rather than a sea level passage and to concentrate on the eradication of yellow fever. Houses were built for the workers and roads paved. The workers lived comfortably, though within a strictly enforced hierarchy of salaries and benefits. All Americans were "Gold Men" paid in gold and lodged in houses; all others were "Silver Men" paid in silver and lodged in barracks. Despite the inequalities, the canal workers shared a spirit of camaraderie. By 1912 more than 40 nationalities worked in the Panama Canal Zone: 30,000 West Indians, 2,000 Italians and 1,000 Greeks among others. These workers faced danger as new technologies were introduced to build the Canal. Thousands of men died from dynamite explosions and mud slides. After eight years of blood, sweat and tears, the Canal opened in 1914 within weeks of the outbreak of WWI.