On April 20th, 2010, at 9:49 PM, the Deepwater Horizon oil rig explodes. For 87 days, more than 200 million gallons of crude oil pump into the Gulf of Mexico, leading to long-term effects on the environment, the local economy, and the health of tens of thousands. Now, in-depth analysis of the catastrophe, investigative reports, and personal testimony from oil workers and residents of the Gulf Coast reveal ten critical mistakes that ultimately led to the greatest environmental disaster in U.S. history.