To get an idea of how dire the situation is in hurricane-battered Puerto Rico, take a look at these before-and-after photos of the island.

The images, from a National Oceanic and Atmospheric Administration satellite, offer aerial views of the US commonwealth. One was taken July 24, the other Monday.

The difference is stark.

Usually the island's coastal towns and cities glimmer in a ring of light. Not anymore.

San Juan and other cities show the dim light of generator power. The island of Vieques is completely dark.

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