When the Deepwater Horizon oil rig exploded, an estimated 4.2 million barrels of oil unleashed havoc on the Gulf of Mexico. The accident occurred 100 miles from Grand Isle, the last inhabited barrier island off the coast of Louisiana. Visiting the island community, Juliet Brown reveals the devastating repercussions of the worst man-made environmental disaster in U.S. history and questions whether the chemically pervasive clean up effort has been more destructive than the spill itself.