Medford, MA (CNN)It's the middle of the day for Eric, a 24-year-old research assistant at the Massachusetts Institute of Technology, and nature is calling.
Eric leaves his job and hops a train. Then a bus. Then he walks some more. He passes countless toilets, and he needs to use them, but he doesn't.
Eventually, Eric arrives at a nondescript men's room 30 minutes away from MIT. A partition separates two toilets. There's a square-tiled floor like in any public restroom. It's unremarkable in every way, with one exception: A pit stop here can save lives.
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