were used to carry excavated material out of the tunnel; other tunnel workers were killed as a result of rock slides, dynamite explosions, and a few drowned due to water inrushes. Of those that survived, several suffered from serious health issues caused by an epidemic of hookworm infection (Ancylostoma duodenale). Medical investigations led to "major advances in parasitology, by way of research into the aetiology, epidemiology and treatment of ancylostomiasis". During 1875, the workforce went on strike; this was promptly violently suppressed by local police force (21 men) from Altdorf, resulting in four deaths amongst the workers and the wounding of 13 others. Consequently, 80 workers left the building site afterwards. During 29 February 1880, it was announced that both of the tunnel's advance borings had broken through into one another around the mountain's middle point. It was also observed that a high degree of accuracy had successfully been achieved, a testament to the stringent surveying and directing that had been performed throughout the construction phase. The occasion was widely publicised and hailed as a major engineering triumph; the engineer Adolphe Gautier described it at the time as being "the greatest work hitherto attempted by man". Following this milestone, a further two years of construction work continued upon the tunnel. This period of activity largely revolved around removing the excess spoil and the completion of its masonry. These finishing works were considered to be relatively low risk compared with the preceding boring that had taken so long, and was actually easier to complete than the approach lines to meet with either end of the tunnel. Operation On 1 January 1882, the Gotthard Tunnel was opened for traffic for the first time. The opening drew substantial international attention; the president of Switzerland, Simeon Bavier, praised the project and declare it to be: "A triumph of art and science, a monument to work and diligence! The barrier which divided nations has fallen, the Swiss Alps have been breached. Countries have moved closer to each other, the world market is open!". Initially, the tunnel was operated by the private railway company Gotthardbahn, which ran conventional trains drawn by steam locomotives between Lucerne and Chiasso at the Italian border. According to Gautier, at the time of the tunnel's construction, there were proposal to operate trains hauled by atmospheric locomotives through the tunnel; however, he voiced his scepticism over the value of doing so in