On April 20, 2010, an explosion and fire aboard an oil drilling platform killed 11 workers and unleashed a massive oil spill in the Gulf of Mexico. Beyond the immediate human tragedy, the Deepwater Horizon disaster has imperiled the ecosystem along the U.S. Gulf Coast and impacted residents who depend on a healthy Gulf of Mexico. The spill raises serious concerns about drilling in sensitive habitats from the Gulf to the Arctic Ocean, as well as broader questions of national energy policy.