On April 20, 2010, the Deepwater Horizon oil rig exploded off the coast of Louisiana. The explosion and subsequent fire killed 11 workers and injured several others, and started the release of millions of gallons of oil into the Gulf of Mexico from more than one mile beneath the surface of the water. It is still too early to tell, but it may very well be the biggest environmental disaster in the history of the United States. Was it foreseeable? Was it preventable? Did a federal law enacted two decades earlier in response to a prior environmental catastrophe set the stage for international oil company executives to pursue dangerous deepwater drilling practices with little fear of economic liability? It will take years and probably many lawyers, judges, and juries to answer these questions, but it is not too early to start asking them.