KUPDHON, Bangladesh—Five weeks after Mahinur Akhter was dragged, bloody and barely conscious, from the broken concrete of the collapsed Rana Plaza garment-factory building, the teenage girl was back in her hometown, trapped between duty and fear.

In the shade of her family's mud-walled house, Ms. Akhter weighed the $90 to $100 a month she could earn as a seamstress against long hours, harsh supervisors and the terror she endured in the rubble.

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