The Los Angeles Times reports: Face down on a roof inside the besieged American diplomatic compound, gunfire and flames crackling around them, the two young Libyan guards watched as several bearded men crept toward the ambassador’s residence with semiautomatic weapons and grenades strapped to their chests.

“We are finished,” one of the guards says he remembers thinking.

Both are veterans of the ragtag revolutionary forces that toppled Moammar Kadafi. Over the last year, while assigned by their militia to help protect the U.S. mission in Benghazi, the pair had been drilled by American security personnel in using their weapons, securing entrances, climbing walls and waging hand-to-hand combat.

They were the “quick reaction force” for a compound that was also protected by about five armed Americans and five Libyan civilians hired through a British firm and equipped only with electric batons and handcuffs.

But nothing, they say, had prepared them for this. They had practiced for an attack by 10 or 15 people; now there were scores of professional-looking militants who moved methodically and used well-practiced hand signals. To make matters worse on the night of Sept. 11, instead of four militiamen who were supposed to be on guard, there were only two inside the compound.

The militiamen say they initially fought back, but when one attacker lobbed a grenade into their bungalow near the compound’s entrance, they fled to the roof without their radios and with only one magazine of ammunition between them. The American security officers were nowhere in sight.

As the raid continued — eventually killing Ambassador J. Christopher Stevens and another American inside the facility, and two other Americans at a separate location hours later — the two Libyans say that they survived by lying on the roof silently for about an hour, too stunned, scared and overmatched to fight back.

“We were not expecting such a massive attack,” the guard says. “We were not ready for it.”

The two militiamen, who spoke to The Times in separate interviews in the last week in Benghazi and Tripoli, the capital, say they are telling their story publicly for the first time in part because FBI investigators are raising questions about their role. One of the militiamen and a civilian guard say investigators asked them why the guards didn’t fight “to the death,” and were looking for signs that the attackers had collaborators within the militia.

The militiamen flatly deny supporting the assailants but acknowledge that their large, government-allied force, known as the Feb. 17 Martyrs Brigade, could include anti-American elements.

American officials have declined, as a matter of protocol, to discuss security arrangements at the outpost in eastern Libya . But the attack — the worst to strike a U.S. diplomatic mission since 1998 — grimly underscored the chaos in post-revolutionary Libya, where an array of heavily armed but unevenly trained militias is serving as a sort of substitute army and is responsible for virtually all security, including at diplomatic outposts. The Feb. 17 brigade is regarded as one of the more capable militias in eastern Libya.

The assault also raised questions about why Stevens, a high-value target who was known to venture into the streets, would have spent the anniversary of the Sept. 11 terrorist attacks at the Benghazi mission instead of the more fortified embassy in Tripoli.

The guards bristle at accusations that they shrank from the fight and say they had repeatedly warned American officials about flawed security arrangements.

“They called me a liar. They said we didn’t see you on the [security] cameras fighting,” says the second militiaman, who was questioned by the FBI recently in Tripoli and who, like others interviewed for this story, asked not to be identified out of fear for his safety.

“I told them that we fired our weapons in the beginning but when we got to the roof, there were 100 enemies and two of us. We could do nothing.”