The obvious economic advantages of bridging the East River were recognized early on in New York history. However, most people considered it to be an impossible feat owing to the width of the East River. One of the biggest considerations for the Brooklyn Bridge was the fact that the East River was one of the busiest waterways in New York; any engineer attempting to design the bridge would have to tackle the challenges of building a high suspension bridge over that long of a distance. In 1857 a prominent engineer and German immigrant John Roebling began to sketch the designs for the bridge connecting the cities of Brooklyn and New York. (At that time, Brooklyn was still a separate city; the consolidation to Greater New York did not take place until 1898.) In 1867 the New York Bridge company was incorporated, and hired John A. Roebling as the engineer for the Brooklyn Bridge. In 1869, just as necessary approvals had been secured to start building, a fatal accident took the life of John A. Roebling when he severely injured his foot, and contracted tetanus. Soon after John Roebling's death, his son Washington Roebling was given the responsibility of engineering the Brooklyn Bridge. There were several concerns over the stability of the bridge that had to be addressed in its design and construction. One of the most striking designs of the Brooklyn Bridge was the two enormous stone towers that stabilized the bridge at each end. Huge wooden structures called caissons were constructed and transported to the East River. Once in the water, these structures were filled with pressurized air to prevent water from seeping inside. At the bottom of these caissons men dug up the bedrock so that the towers of the bridge would sit firmly in the bedrock of the East River. The working conditions inside the caissons were difficult; the highly pressurized air could cause decompression sickness, or the bends. Since electric light had not yet been invented, illumination came by way of gas lights, adding the risk of fire and making it very difficult for the men to work in dim light. In the summer of 1872 Washington Roebling became a victim of the bends while he was supervising the work in the western caisson, causing permanent paralysis. Despite this set back, the younger Roebling continued to supervise the building of the bridge through the help of his wife Emily Warren Roebling, who helped relay his messages to workers and managers at the construction site. In 1878, further difficulties emerged when Roebling discovered that one of the suppliers had sold him defective wire rope that was woven into the cables supporting the bridge. To adjust for the faulty cables, Roebling installed additional steel cables, which were made to be six times stronger than necessary for it to support the bridge. On May 24, 1883 the bridge that had taken 14 years to build was finally ready to be unveiled to the public. The creation of the Brooklyn Bridge not only changed the course of history for New York City, it also affected the lives of thousands of commuters between Brooklyn and Manhattan.