"The explosion and fire aboard the Deepwater Horizon and the resulting oil spill in the Gulf of Mexico never should have happened, and I am deeply sorry that they did," Hayward said in prepared remarks before the House Committee on Energy and Commerce's Subcommittee on Oversight and Investigation.
Hayward, who drew ire for his "I want my life back" comment earlier, said he understands how serious the situation is in along the U.S. Gulf Coast, where oil has been fouling water, marshes, beaches and wildlife since April 20, when the Transocean Deepwater Horizon rig leased by BP exploded, killing 11 workers. The rig sank two days later, creating the worst oil spill in U.S. history.
"This is unacceptable, I understand that," Hayward said, "and let me be very clear: I fully grasp the terrible reality of the situation."
However, as he took questions from members of Congress, Hayward repeatedly denied knowledge of whether the company took unnecessary risks to save time and money on the drilling project, The New York Times reported.
"I had no prior knowledge of the drilling of this well, none whatsoever," he said.
He declined to speculate on the cause of the explosion or who was responsible.
At one point, Rep. Henry Waxman, D-Calif. -- chairman of the House Energy and Commerce Committee -- accused Hayward of "stonewalling."
"I'm not stonewalling," Hayward said. "I simply wasn't involved in the decision-making."
Hayward had been forewarned by Waxman that he would be asked about internal documents that seemed to indicate "BP repeatedly took shortcuts that endangered lives and increased the risks of a catastrophic blowout."
Waxman said a review of documents didn't yield any evidence "that you paid any attention to the tremendous risks BP was taking."
Rep. Joe Barton, R-Texas, ranking Republican of the full committee, said during his remarks he was ashamed of what happened during Wednesday's meeting between President Barack Obama and BP officials, after which BP agreed to establish a $20 billion claims fund.
"I'm speaking now totally for myself," Barton said. "I think it is a tragedy of the first proportion that a private corporation can be subjected to what I would characterize as a shakedown, in this case, a $20 billion shakedown … ."
Barton apologized to BP and said there was "no question" that BP owned the lease, made decisions "that objective people think compromised safety," and that BP was liable for damages.
"I do not want to live in a country where any time a citizen or a corporation does something that is legitimately wrong is subject to some sort of political pressure that is -- again, in my words, amounts to a shakedown. So I apologize."
Rep. Ed Markey, D-Mass., disagreed with Barton, saying, the fund was not a shakedown but the U.S. government protecting the gulf residents and businesses.
"No, this is not a shakedown of the company," Markey said. "This is the American government, President Obama, ensuring that this company is made accountable and sending a signal to all other companies that seek to treat ordinary American families in a way that can destroy their entire family's history. This is, in my opinion, the American government working at its best."
Later in the day, under pressure from Republican leaders, Barton issued a statement retracting his apology and acknowledging BP is "responsible for this accident."