On the frontlines of the fight to preserve the world's largest tropical rainforest. "The Amazon holds the largest biodiversity on the planet. The Amazon is the home of hundreds of thousands of plant and animal species." Nobel prize winner The Amazon is one of the most precious natural habitats in the world and plays a vital part in regulating the planet's temperature. So when alarming pictures emerged last year of the Amazon on fire, the world was shocked. These fires were so big they could be seen from space, leaving many to ask how could this have happened? Why wasn't the forest being protected? On Monday Four Corners takes you on an epic journey through the Brazilian Amazon to investigate.