Shocking Drone Footage Shows Harvey's "Unprecedented" Devastation, "No Parallel To Any Rainstorm In US History"
Based on the number of people affected, amount of water involved, and other factors, meteorologists have warned, there may be no parallel available to any other rainstorm in U.S. history as Mashable's Andrew Freeman reports Tropical Storm Harvey has dropped more than 11 trillion gallons of water on Texas, triggering catastrophic, unprecedented flooding in the Houston area.