The hearings began with members of the House Committee on Foreign Affairs offering their condolences to the families of the four deceased and calling for answers and accountability.
“I think we need to have a real honest explanation of what happened," said Congresswoman Jean Schmidt. The hearing is an important step toward achieving accountability, said Congressman David Rivera.
Michael Courts, acting director of International Affaird and Trade, is the first witness to provide testimony.
Congressman Brad Sherman asked Courts if he was aware of a deliberate attempt to mislead the American public about what happened during the attack. Courts said he was not in a position to address that issue as his testimony was primarily based on a Government Accountability Office report and “GAO’s work did not address that issue."
Three other witnesses are scheduled to appear today, including the president of the American Academy of Diplomacy.
The hearings on Capitol Hill will focus on the "intelligence collection and threat reporting relating to Libya and other Middle East countries prior to the Sept. 11 attack, how and when that information was disseminated and what actions were taken in response," the committee said in a statement.
It will also examine the level and adequacy of security at the State Department and other U.S. facilities in the region, it added.
High-profile officials, including the director of the FBI, will testify before congressional committees about what they know of the attack.
On Friday, the committee is expected to hear from David Petraeus, the retired four-star general who resigned as head of the CIA last week after admitting to an extramarital affair with his biographer.
'He didn't tell the truth'
Questions about the handling of that attack — and when the Obama administration knew it was a terror attack — was a key and contentious issue during the U.S. election, and sparked verbal clashes between the president and Republican Senator John McCain on Wednesday.
"He didn't tell the truth to the American people at one time or another," he said to reporters.
McCain and fellow Republican Lindsay Graham accused the U.S. ambassador to the UN, Susan Rice, of knowing that it was a terror attack and not a demonstration that turned violent, which she called it days later.
During a press conference in Capitol Hill, McCain and Graham said Rice intentionally misled the country, and if the president nominated her as the his Secretary of State, they would attempt to stop it.
"I think she knew better, and if she didn't know better, she shouldn't be the voice of America," Graham said.
President Barack Obama, in his first media conference since his re-election last week, fiercely defended Rice.
"She gave her best understanding of the intelligence that had been provided to her … To besmirch her reputation is outrageous," he said.