until before and after satellite pictures proved what they already knew. 98% of isle dejean charles, louisiana, has disappeared. i always talk about water is our life and death. once we weren t able to farm anymore, the waters, the shrimp, oysters, crabs, that sustained our people. now it s killing us. it s killing us. reporter: every hour of every day, a piece of louisiana about the size of a football field slips into the sea. every hour. every day. it started when america tamed, locked and diked the mighty mississippi choking off the natural flow of mud that built this land. these days, as it sinks, polar ice amendmemelts, seas rise, bis keep coming. there s been a lot of change in just the last five years. reporter: those who study the drowning of louisiana say it is happening faster than anyone ever predicted.