fiery confrontation was under way over libya and that night four americans lost their lives, including u.S. Ambassador chris stevens. Tonight, new revelations about the terrorists, thor e er if... See More
fiery confrontation was under way over libya and that night four americans lost their lives, including u.S. Ambassador chris stevens. Tonight, new revelations about the terrorists, thor e er if rferocity of their attack and new questions about whether life-saving security was denied. Abc's jake tapper has details. Reporter: That horrifying night in benghazi had former security officials in libya today condemning their superiors for denying their requests for more security agents. I asked for 12 agents, his response to that was, "you are asking for the sun, moon and the stars." Reporter: Eric nordstrom, the former security officer at the u.S. Embassy in libya, today recalled his biggest frustration as being the state department. It is dealing and fightin against the people, programs and personnel who are supposed to be supporting me. For me, the taliban is on the inside of the building. Reporter: Nordstrom suspected the denials for more security were rooted in a fear of making libya seem more unstable. But a state department official denied any politics were at play. I have directly served six secretaries of state, democratic and republican. On my honor, no. None. eporter: WE'VE LEARNED NEW Details of what happened that night. At 8:30, ambassador chris stevens went outside the compound to say good night to a visitingturish diplomat. The streets were empty. But at 9:40 p.M., Security agents in the operations center heard explosions and saw a large group of armed men entering the compound. Stevens, information specialist sean smith and one security agent locked themselves in a safe area -- they saw their attackers hunting for them. Then, pouring diesel and setting the house on fire. The three americans went to a bathroom area where they tried to open a small window for air, but it was not enough. On the ground, suffering from severe smoke inhalation, they decided to flee. But stevens and smith never made it out alive. Diane sawyer asked the president about the white house's initial claims that the incident began with a protest against that anti-muslim video. As information came in, information was put out. The information may have not have always been right the first time. Look -- diane, these are people I know. And if there's something to be fixed, it'll get fixed. Reporter: The commander of a security team pulled from libya weeks before the attack said that when he heard about the attack, it was instantly recognizable that it was terrorists. "I almost expected the attack to come," he said. "We were the last flag flying. It was a matter of time."
This transcript has been automatically generated and may not be 100% accurate.