Officials still don't have an agreed upon number of storm-related casualties from Hurricane Maria, which slammed the island of Puerto Rico on Sept. 20, 2017, causing massive destruction to the island's infrastructure and knocking out the entire power grid.
Why it matters: Now a new study, published in the New England Journal of Medicine on Monday, finds a far higher estimate for the actual death toll, 4,645, than the official estimate of just 64.
Flash flooding from a massive rainstorm rushed through Main Street on Sunday in Ellicott City, Md., which was severely ravaged by flood waters just two years ago.
Why it matters: Sunday's and 2016 flooding likely rank as greater than 1-in-1,000 year rainstorms, which means than in any given year there's just a 0.1 percent chance of them occurring, Axios science editor Andrew Freedman explains. By adding more moisture to the air available for storms, climate change is leading to a well-documented uptick in heavy rain events, particularly in the Northeast. Human development patterns are also elevating flood risk in many areas.
