By Ian Yarett and Kathy Jones
Official estimates now say the Deepwater Horizon disaster is the largest accidental release of oil in world history. After the rig sank into the Gulf of Mexico on April 22, it dumped as much as 4.9 million barrels of oil into the sea before its broken well was capped in mid-July. Response teams continue to work on cleaning up the floating oil and minimizing the amount that hits land. Although BP officials say they have stopped the flow from the spill, oil is still washing up on the delicate shoreline, has closed down fisheries and continues to threaten the region's fragile ecosystems.
Related story: How to help the gulf recover from the oil spill.