Some are calling the BP oil spill the worst environmental disaster in US history, but I wonder if that's really true. It seems to me that the 1930s Dust Bowl was far greater in the impact on its area and its inhabitants, and on the country as a whole.
True, nature had a bigger role, with a drought over the southern midwest. But mankind had a big role too, as a lack of rotation farming and other mistakes sharply exacerbated the problem. Hundreds of thousands of people were utterly wiped out, and at a time when government support was nothing like today.
That's not to underplay the severity of the oil spill in the Gulf of Mexico, of course. But I can't see a book like The Grapes of Wrath coming out of it.