Extreme building : Grand Canyon SkyWalk

Glass Bridge will be suspended 4,000 feet above the Colorado River on the very edge of the Grand Canyon. On May 2005, the final test was conducted and the structure passed engineering requirements by 400 percent, enabling it to withstand the weight of 71 fully loaded Boeing 747 airplanes (more that 71 million pounds). The bridge will be able to sustain winds in excess of 100 miles per hour from 8 different directions, as well as an 8.0 magnitude earthquake within 50 miles.

More than one million pounds of steel will go into the construction of the Grand Canyon SkyWalk.

source : http://stranges-world.blogspot.com/search/label/strangest