Horrifying Urban 'Surprise' of the Day: A Fiery Hole in a London Sidewalk

Of all the urban phobias, fear of the sidewalk exploding beneath you seems like one of the most irrational.

True, it very rarely happens. But when it happens, it's awful. And when it happens with some frequency, as in Rio de Janeiro, the fear spreads -- there's even a word for it (kind of): manholia.