A straight line marks a pipeline, July 26, 2001, beneath the surface of the Gulf of Mexico, in this aerial photo. Pipelines from oil and gas rigs go deep beneath the Gulf of Mexico to carry the oil and gas off of the many different wells, platforms and towers that dot the Gulf. The pipelines then cross the many marshes and bayous on the Louisiana coast to bring the product to shore.

Many pipelines running from offshore rigs suffered serious damage when Katrina and Rita tore the rigs lose — severing pipeline connections or tearing up pipes when the rigs' massive anchors were dragged across the sea floor. There was relatively little leakage since the pipelines were shut down as a precaution when the hurricanes approached.