Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
Former President Jimmy Carter and Rev. Jesse Jackson remember Nelson Mandela.
For eight months, the families waited, and at times begged through tears, for answers to the question: What happened in Benghazi?
On Wednesday, Mark Thompson, acting deputy assistant secretary of state for counterterrorism; Eric Nordstrom, former regional security officer in Libya; and Greg Hicks, former deputy chief of mission in Libya, testified before a House committee. The witnesses spoke of the terror attack of last September 11, the Obama administration's response to it, what happened before the post in Benghazi was surrounded by fire, and how the White House didn’t get its message straight after the attack.
The attack killed Christopher Stevens, U.S ambassador to Libya; State Department information officer Sean Smith; and former Navy SEALs Tyrone Woods and Glen Doherty.
"I cry every night. I don't sleep at night," Pat Smith, Sean’s mother, said this week. "I need answers."
Watch "The Lead" on CNN at 4 p.m. for our follow-up interview with Pat Smith, mother of Sean.
The men who testified Wednesday challenged the Obama administration’s version of events leading up to and after the terror attack. The investigation must continue, Nordstrom said.
"The committee's labors to uncover what happened prior, during and after the attack matter. It matters to me personally, and it matters to my colleagues, to my colleagues at the Department of State," an emotional Nordstrom said.
When Susan Rice, U.S. ambassador to the United Nations, appeared on TV days after the attack and blamed it on protests to an anti-Islam YouTube video, Hicks said he was shocked.
"I was stunned. My jaw dropped and I was embarrassed," said Hicks, who became emotional speaking about the death of his friend Stevens.
"I received a phone call from the prime minister of Libya. I think it's the saddest phone call I had ever heard in my life. He told me that Ambassador Stevens had passed away," Hicks said, fighting back tears. "I immediately telephoned Washington after the news and began accelerating our effort to withdraw and move the annex."
Before the attack, the State Department repeatedly denied requests from diplomats on the ground for additional security, according to internal State Department e-mails.
"It was clear that in some ways the State Department got used to the notion that its primary responsibility was to live within its budget," Thomas Pickering, a former U.S. ambassador, told CNN’s Jake Tapper. Pickering is co-chairman of the State Department’s Accountability Review Board that issued a report on Benghazi in December.
"The changing situation in Benghazi was not understood either on the ground, or in Washington to the degree to which it represented a danger," Pickering said.
That changing situation was marked by 42 incidents, including bomb attacks, assassination attempts and gunbattles, against foreigners between April and September 11, events that were not properly evaluated, Pickering said.
"They obviously pointed to a changing situation, they seemed to be dismissed by a kind of culture of comfort, as we described it in the report," Pickering said.
It now appears Stevens was sent to Benghazi despite the increasingly dangerous situation.
"According to Chris, Secretary (Hillary) Clinton wanted Benghazi converted into a permanent constituent post. Timing for this decision was important. Chris needed to report before September 30, the end of the fiscal year on the political and security environment in Benghazi to support an action memo to convert Benghazi from a temporary facility to a permanent facility," Hicks testified.
Benghazi was significant for U.S. interests, Pickering said.
"People from Benghazi had led the revolution against (Moammar) Gadhafi; they played an enormously important role in the continuing government in Tripoli and Libya, and it was very significant for the U.S. and for Ambassador Stevens to continue to have his excellent relationship with them," Pickering said.
As to whether more could have done during the attack, Pickering said the board looked closely at the military air assets, and other assets, reviewing the attack with the military in extensive detail.
"Despite the fact that we have the world's best military, they were neither postured nor placed in a way that could have made a significant difference," Pickering said. "It's regrettable, but it is truth and it is honesty."
U.S. Rep. Darrell Issa, chairman of the House Oversight and Government Reform Committee, said at Wednesday's hearing that Pickering and retired Adm. Mike Mullen, vice chairman of the Accountability Review Board, were asked to testify or speak with the committee informally, and they refused. Pickering disputes that account.
"I was fully prepared to come and participate in any way at all," Pickering said. "Chairman Issa replied back that maybe sometime in the future he would have hearings that he could include me, and I was disappointed, ready to come at any time, obviously, to participate in those hearings."