Lake Okeechobee at the heart of Florida's Everglades is home to a vast array of animals and plants. But now, this tropical wilderness is drowning. On the heels of Hurricane Irma, a record-breaking wet season has led to the worst flooding in 70 years. That's making the lake deeper - which is bad news, not only for hundred of species that depend on it, but also for Florida's supply of fresh water.