What killed Stacy Ruffin?

Updated 6:14 AM ET, Fri August 11, 2017

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John D. Sutter is a columnist for CNN who focuses on climate change and social justice. Follow him on Snapchat, Twitter and Facebook.

Arcola, Louisiana (CNN)Rain pounded on the roof of the mobile home as the phone rang. The call was about Mark, Carolyn Ruffin's oldest son. He'd been hospitalized in a nearby town. The mother of four, who normally has an unflappable air about her, knew she had to rush to her boy -- no matter that a storm was brewing, the likes of which her corner of Louisiana never had seen.

This was August 12, 2016. In the next week, about 7 trillion gallons of water would fall on Louisiana, more than during Hurricane Katrina, according to meteorologist Ryan Maue. The nameless storm would shatter records, flood homes and kill 13 people.
That morning, though, Carolyn's thoughts weren't focused on the weather. They were with her son. So, at about 7 a.m., she hopped in the front seat of a friend's pickup truck.
Two people would join her. One was Alfred Waxter, the truck's owner, a close family friend visiting from Mississippi. The other was Carolyn's daughter Stacy.
At 44, Stacy Ruffin was the youngest of Carolyn's four children. Family members speak of the two as inseparable, and they mean it literally. Stacy lived with her mother in the mobile home, raising a daughter and son of her own there. She managed the deli counter at the Walmart in a neighboring town. Otherwise, she was at her mother's side, helping run errands, pay bills, check on neighbors. Stacy's eight aunties and uncles -- and their children -- all were part of her flock.
She was the family caretaker. The responsible one. The one you turned to.
    So it's no surprise she went with her mother to check on her brother.
    And it's no surprise that, one year after the storm, no one has filled her void.

    'Natural' disaster

    Hundreds of miles away, the email landed in the scientists' inboxes.
    It was four days later, August 16. The request: Would Karin van der Wiel, Sarah Kapnick and Gabriel Vecchi -- three researchers from the US National Oceanic and Atmospheric Administration's lab in Princeton, New Jersey -- help assess the extreme rainfall in Louisiana?
    The floods in Louisiana had caught the attention of the World Weather Attribution team coordinated by Climate Central, a nonprofit that focuses on climate change science and journalism. And they wanted help.
    The team would be assessing the Louisiana storm for any signs of climate change. Was this storm more likely because humans are polluting the atmosphere with heat-trapping gases? Did climate change have any likely influence on the extreme rainfall totals? Or was this a truly "natural" disaster?
    Karin and Sarah considered the proposal.
    The result of their inquiry would be published no matter what they found, but they had to work fast. Scientific studies typically play out over months, if not years. Could this massively complicated work be done -- and quickly enough to capture the public's attention?
      The researchers knew they'd have to drop everything else to focus on this project. But they had the expertise, and they had the climate models at NOAA's Geophysical Fluid Dynamics Laboratory.
      Plus, there was something about this flood.
      It seemed to have the drenching power of a tropical storm, yet it stalled on land, dumping trillions of gallons of water on southeastern Louisiana, day after day. All three scientists had seen the news coverage: the floating c