Answer:
its declined because people have now become scared and have no need to fight that or people are just more focused on other stuff
Explanation:
Hoover Dam<span>, once known as Boulder Dam, is a concrete arch-gravity dam </span>in<span> the Black Canyon ....</span>Construction<span> of a rail line joining Las Vegas and the dam site began </span>in<span> September </span>1930<span>. .... Falling objects were the most common cause of death on the dam site; the highscalers' work thus </span>helped<span>ensure</span><span> worker safety</span>
The first permanent settlement was Jamestown.
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