BP CEO Tony Hayward is sworn in on Capitol Hill in Washington, Thursday, June 17, 2010, prior to before testifying before the Energy and Environment subcommittee on Oversight and Investigations hearing on the role of BP in the Deepwater Horizon Explosion and Oil Spill. [Agencies]

Since 1990, oil and gas industry political action committees and employees have given more than $1.4 million to Barton's campaigns, the most of any House member during that period, according to the nonpartisan Center for Responsive Politics.

With multiple investigations continuing and primary efforts in the Gulf focused on stopping the leak, there was little chance the nation would learn much from Hayward's appearance about what caused the disaster. Yet even modest expectations were not met as the CEO told lawmakers at every turn that he was not tuned in to operations at the well.

He said his underlings made the decisions and federal regulators were responsible for vetting them.

Hayward spoke slowly and calmly in his clipped British accent as he sought to deflect accusations — based on internal BP documents obtained by congressional investigators — that BP chose a particular well design that was riskier but cheaper by at least $7 million.

"I wasn't involved in any of that decision-making," he said.

Were bad decisions made about the cement?

"I wasn't part of the decision-making process," he said. "I'm not a cement engineer, I'm afraid."

Also, "I am not a drilling engineer" and "I'm not an oceanographic scientist."

What about those reports that BP had been experiencing a variety of problems and delays at the well?

"I had no prior knowledge."

At one point a frustrated California Rep. Henry Waxman, Democratic chairman of the House Energy and Commerce Committee, interrupted the CEO. "You're kicking the can down the road and acting as if you had nothing to do with this company and nothing to do with the decisions. I find that irresponsible."

Hayward quietly insisted: "I'm not stonewalling. I simply was not involved in the decision-making process."

Rep. Eliot Engel, D-N.Y., voiced the committee's frustrations as the afternoon wore on. "You're really insulting our intelligence," he said. "I am thoroughly disgusted."

Waxman told the BP executive that in his committee's review of 30,000 items, there was "not a single e-mail or document that you paid even the slightest attention to the dangers at this well."

Burgess slammed both the CEO and the government regulators for a risky drilling plan that he said never should have been brought forward.

"Shame on you, Mr. Hayward, for submitting it," he said, "but shame on us for accepting it, which is simply a rubber stamp."

As Hayward began to testify, a protester disrupted the hearing and was forcibly removed from the room by Capitol police. The woman was identified as Diane Wilson, 61, a shrimper from Seadrift, Texas, near the Gulf Coast. Her hands stained black, she shouted to Hayward from the back of the room: "You need to be charged with a crime."

Stupak, the subcommittee chairman and a former Michigan state trooper, noted that over the past five years, 26 people have died and 700 have been injured in BP accidents -- including the Gulf spill, a pipeline spill in Alaska and a refinery explosion in Texas.

Hayward argued that safety had always been his top priority and "that is why I am so devastated with this accident." When he became CEO in 2007, Hayward said he would focus "like a laser" on safety, a phrase he repeated on Thursday.

Rep. John Sullivan, R-Okla., questioned BP's commitment to safety.

BP had 760 safety violations in the past five years and paid $373 million in fines, Sullivan said. By contrast, Sunoco and ConocoPhillips each had eight safety violations and ExxonMobil just one, Sullivan said.

"How in the heck do you explain that?" he asked Hayward. Hayward said most of those violations predated his tenure as CEO. "We have made major changes in the company over the last three to four years," he said.

As of Thursday morning, the BP well had sent 66 million to 120 million gallons of oil into the Gulf of Mexico, based on government daily spill rate figures.