The mayor of Mississippi's biggest city urged residents to "get out now" on Saturday as record-setting rain threatens to flood streets and creep into homes within the next two days.

Niagara Falls is the latest natural wonder to add a zip line, offering honeymooners and everyone else the chance to take an adrenaline-pumping plunge toward churning mist at speeds topping 40 mph. The elevated cable rides have evolved from a novel way to explore jungle canopies to almost necessary additions to lure tourists in the 21st century to established destinations. It's a trend that's exposed a rift between those who approach nature like contemplative monks and others who require an extreme, Indiana Jones-style experience.