A magnitude 5.9 quake shook Puerto Rico on Saturday, causing further damage along the island's southern coast, where previous recent quakes have toppled homes and schools. Puerto Rico's Electric Power Authority said outages were reported across much of southern Puerto Rico and crews were assessing possible damage at power plants.

The U.S. Geological Survey said the 8:54 a.m. quake hit 8 miles southeast of Guanica at a shallow depth of 3 miles. The quake, which initially had been calculated at magnitude 6.0, was the strongest shake yet since a magnitude 6.4 quake — the strongest to hit the island in a century — struck before dawn on Tuesday, knocking out power across Puerto Rico and leaving many without water.

Thousands have stayed in shelters and slept on sidewalks since Tuesday's earthquake, which killed one person, injured nine others and damaged or destroyed hundreds of homes and several schools and businesses in the island's southwest region.

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Since December 28, there have been nearly 2,000 earthquakes in Puerto Rico, 60 of which were felt. Scientists warned this week it was impossible to predict when the tremors would stop.

The tremors are the latest blow to a community that is still feeling the lasting devastation of Hurricane Maria.