The need to transport coal, oil, and lumber across the Kinzua Valley led General Thomas Kane, president of the New York, Lake Erie and Western Railroad and Coal Company, and Octave Chanute, chief engineer for the Erie Railroad, to design the Kinzua Bridge, a colossal viaduct built by 125 men in just 24 days and completed in 1882 as the tallest viaduct in the world at 301 feet, 24 feet higher than the Brooklyn Bridge. Billed as the "Eighth Wonder of the World," it quickly became both a successful route for carrying Kane's coal across the valley and a popular tourist attraction, with train excursions offering a thrilling crossing. Around 1900, the original iron bridge was replaced with a steel structure to handle heavier modern trains, and freight trains continued to cross it until 1959. Excursion trains returned in 1987, carrying riders through the Allegheny National Forest and across the span known as the "Tracks Across the Sky." On July 21, 2003, winds of up to 112 mph tore hundreds of trees from their roots and hurled 11 of the bridge's 20 towers onto the valley floor, bringing the great span down in 30 seconds. Today, a sky walk built on six restored towers allows visitors to walk part of the bridge again, while the mile-long General Kane Trail, named for General Thomas Leiper Kane, passes through black cherry and chestnut hardwood forests and areas both damaged and renewed by nature since the 2003 tornado.