CNN News:美国也有电梯事故 回顾电梯发展史

Earlier this month, the group of about 15 people reportedly got stuck in an elevator in Chicago's Willis Tower. In a separate incident, some USC football players who exceeded in elevator's weight limit got stuck in California.
What the two groups had in common besides the elevators are the safety measures that helped them all get out OK. They can thank a man named Otis.
RACHEL CRANE, cnn CORRESPONDENT: Drop a working stiff from the 19th century and modern day New York, what's the first thing he might notice?
Height. It's in the last century, cities across the world have gotten taller, much, much taller.
At the start of the 20th century, you'd be hard-pressed to find a building that was more than six stories high. Who wants to hop up a flight of stairs longer than that?
But then, the modern elevator arrived. And builders raced towards the heavens, constructing massive office skyscrapers containing millions of square feet.
Sure, the basic idea was nothing new. Primitive elevators have been around since 236 B.C., but they relied on manpower, lots of it.

By the mid-19th century, elevators were deriving their power from water and steam. But the ropes that they relied on weren't so reliable. And that's where Otis comes in. He developed a safety break that kept the elevator from freefalling of the rope broke.
It was an innovation that transformed business. Not only could people be shuttled up and down, but so could heavy freight. Now, companies could consolidate all of their operations and office furniture in a single building, and that improve accountability, communication and efficiency.
Employees could shuttle from one department to another with a push of a button and a short vertical ride.
Industries likewise didn't have to compete for geographically important locations. In the 1860s, New York City's financial district was so overcrowded, they considered moving it uptown. But then the elevator came along and allowed Wall Street o grow up. Today, there are an estimated 900,000 elevators in America alone, making 18 billion trips a year, and occasionally giving me vertigo.