As the oil spill claims its first victims and response teams scramble to control a leak that could take months to plug, attention is turning to how the oil spilled in the first place.

The White House has its eye trained on one target. Visiting Venice, Louisiana yesterday, President Obama said, "Let me be clear: BP is responsible for this leak; BP will be paying the bill." The oil conglomerate confirmed today that it would be paying for all clean-up costs, as required by law.

Back in Washington, investigations are gearing up to uncover what went wrong. The cause of the initial rig explosion is not yet clear, but investigators will zero in on a piece of equipment that did not pull its weight: the "blow-out preventer." This enormous tower of machinery rests on the ocean floor beneath the rig and was supposed to seal the well during an emergency. Officials do not yet know whether its failure to do so was a result of the accident or of faulty manufacturing.

BP and TransOcean, the Swiss company who owned and operated the Gulf rig, will also be scrutinized for negligence and spotty safety records. BP's record has improved from 2005, when an explosion at the company's Texas City refinery killed 15 workers and injured 170 others. Since then it has been caught leaking oil into Alaska's Prudhoe Bay and manipulating the market price of propane. According to ProPublica, BP cut 5,000 jobs in 2009 in order to save $4 billion in operating costs. As oil streamed into the Gulf last week, the company announced that these cuts had paid off: its quarterly earnings were up more than 100 percent from the year before, a fitting follow-up to last year, during which it significantly outperformed its competitors.

TransOcean, meanwhile, cut executive bonuses last year to encourage improvement on the safety front. During 2009, four workers had died on-site at four different TransOcean locations. Other than these fatalities, the company's safety record is mixed. Its number of accidents per hours worked was lower than the industry average in 2009, though its internal count of potentially dangerous accidents increased by 31 percent.  

BP, for its part, is eager to deflect some of the Obama administration's pointed blame on its Swiss partner. On Good Morning America, BP CEO Tony Hayward said that "the drilling rig was TransOcean's drilling rig, it was their equipment that failed, it's their systems, their processors that were running it."