Executives from the three companies involved with the April 20 Gulf of Mexico rig explosion told lawmakers on Tuesday they're doing everything they humanly can to stop the massive oil spill and figure out why the rig blew in the first place, but while insisting that a collaborative effort is the only way to determine the cause of the explosion, cooperation seemed elusive.
Lamar McKay, chairman of BP America, told the Senate Energy and Natural Resources Committee, that his company was focused on a critical safety device that was supposed to shut off oil flow on the ocean floor in the event of a well blowout but which "failed to operate."
"That was to be the fail-safe in case of an accident," McKay said, pointedly noting that the 450-ton blowout protector -- as well as the rig itself -- was owned by Transocean Ltd.
Of the 126 people on the Deepwater Horizon rig when it was engulfed in flames, only seven were BP employees, said McKay.
But Steven Newman, CEO of Transocean, which owns the rig, suggested it wasn't his company at fault.
"The most significant clue is that these events occurred after the well construction process was essentially complete. Drilling had been finished on April 17 as the well had been sealed with casing and cement. For that reason, the one thing we do know is that on the evening of April 20 there was a sudden, catastrophic failure of the cement, casing or both," Newman said.
"Without a failure of one of those elements, the explosion could not have occurred. It is also clear the drill crew had little if any time to react. The initial indications of trouble and the subsequent explosion were almost instantaneous."
But Tim Probert, an executive with Halliburton Inc., the subcontractor responsible for encasing the well pipe in cement before plugging it -- a process dictated by BP's drilling plan -- said his company finished its work "in accordance with the requirements" set out by BP
He said pressure tests were conducted after the cementing work was finished to demonstrate well integrity.
While the hearings are under way, BP is looking for new ways to plug the gushing leak after plans to cap it with a 100-ton containment box failed. The company is trying another tactic, which involves plugging the leak with trash and, if that works, filling the well with mud and cement.
McKay said the first of two relief wells is being drilled and a second is to begin later this week
Ahead of the testimony, lawmakers debated among themselves the impact of the spill on drilling.
Sen. Jeff Bingaman, D-N.M., chairman of the Senate Energy and Natural Resources Committe, said it is not enough "to label this catastrophic failure an unpredictable and unforeseeable occurrence."
Alaska Sen. Lisa Murkowski, the panel's top Republican, said it is essential to determine if the rig operators followed regulations and the law. But she said the accident should not interfere in continued offshore oil development.
The morning hearing by the Energy and Natural Resources Committee and the afternoon session before the Environmental and Public Works Committee give lawmakers their first chance to question the executives publicly about the rig fire, attempts to stop the flow of oil and efforts to reduce the damage.
BP and Transocean are also conducting separate investigations into what went wrong.
But while the environmental and economic damages have yet to unfold completely, Tuesday's hearings could take on a showboating quality as recent hearings with executives from Toyota, in trouble for faulty braking systems, and Goldman Sachs, in trouble for fraud charges, offered more corporate condemnation than problem-solving.
"I hear one message -- don't blame me," said Sen. John Barrasso, R-Wyo. "Shifting the blame game doesn't get us very far."
"We are all in this together," Murkowski added, warning that without cooperation none of the companies will be in business.
Separately, Interior Secretary Ken Salazar is proposing splitting up the Minerals Management Service. One agency would be charged with inspecting oil rigs, investigating oil companies and enforcing safety regulations, while the other would oversee leases for drilling and collection of billions of dollars in royalties.
A senior administration official told Fox News that legislation is not required for the change.
"DOI has the authority to implement changes" by itself, the official said.
The administration's outer-continental shelf drilling plan still cannot technically be characterized as on hold, though Salazar is conducting a review of drilling safety. The official left open the door for the drilling plan to be nixed, saying, "Everything could be informed and impacted by the 30-day DOI review."
The Associated Press contributed to this report.