In the mid-19th century, suspension bridges  were collapsing all across Europe. Their industrial cables  frayed during turbulent weather and snapped  under the weight of their decks. So when a German-American engineer  named John Roebling proposed building the largest  and most expensive suspension bridge ever conceived  over New York’s East River, city officials  were understandably skeptical. But Manhattan  was increasingly overcrowded, and commuters from Brooklyn  clogged the river. In February of 1867, the government  approved Roebling’s proposal. To avoid the failures  of European bridges, Roebling designed  a hybrid bridge model. From suspension bridges, he incorporated large cables supported by  central pillars and anchored at each bank. This design was ideal  for supporting long decks, which hung from smaller vertical cables. But Roebling’s model  also drew from cable-stayed bridges. These shorter structures  held up their decks with diagonal cables that ran directly to support towers. By adding these additional cables,  Roebling improved the bridge’s stability, while also reducing the weight  on its anchor cables. Similar designs had been used  for some other bridges but the scope of Roebling’s plan here dwarfed them all. His new bridge’s deck spanned over 480 meters— 1.5 times longer than any previously built suspension bridge. Since standard hemp rope  would tear under the deck’s 14,680 tons, his proposal called for  over 5,600 kilometers of metal wire to create the bridge’s cables. To support all this weight, the towers would need to stand  over 90 meters above sea level— making them the tallest structures  in the Western Hemisphere. Roebling was confident  his design would work, but while surveying the site in 1869, an incoming boat  crushed his foot against the dock. Within a month,  tetanus had claimed his life. Fortunately, John Roebling's son,  Washington, was also a trained engineer and took over his father’s role. The following year, construction  on the tower foundations finally began. This first step in construction  was also the most challenging. Building on the rocky river bed involved  the use of a largely untested technology: pneumatic caissons. Workers lowered these airtight  wooden boxes into the river, where a system of pipes pumped  pressurized air in and water out. Once established, air locks  allowed workers to enter the chamber and excavate the river bottom. They placed layers of stone  on top of the caisson as they dug. When it finally hit the bedrock,  they filled it with concrete, becoming the tower’s  permanent foundation. Working conditions in these caissons  were dismal and dangerous. Lit only by candles and gas lamps,  the chambers caught fire several times, forcing them to be evacuated and flooded. Even more dangerous was  a mysterious ailment called "the bends." Today, we understand this  as decompression sickness, but at the time, it appeared to be  an unexplainable pain or dizziness that killed several workmen. In 1872, it nearly claimed the life  of the chief engineer. Washington survived,  but was left paralyzed and bedridden. Yet once again,  the Roeblings proved indomitable. Washington’s wife Emily  not only carried communications between her husband and the engineers, but soon took over  day-to-day project management. Unfortunately,  the bridge’s troubles were far from over. By 1877, construction was over budget  and behind schedule. Worse still, it turned out  the bridge’s cable contractor had been selling them faulty wires. This would have been a fatal flaw  if not for the abundant failsafes in John Roebling’s design. After reinforcing the cables  with additional wires, they suspended the deck  piece by piece. It took 14 years, the modern equivalent  of over 400 million dollars, and the life’s work  of three different Roeblings, but when the Brooklyn Bridge  finally opened on May 24, 1883, its splendor was undeniable. Today, the Brooklyn Bridge  still stands atop its antique caissons, supporting the gothic towers  and intersecting cables that frame a gateway to New York City.