"We're here to kill Americans": Witness on Benghazi attack

(CBS News) We're hearing for the first time from a security officer who witnessed the terrorist attack on the U.S. diplomatic mission in Benghazi, Libya, last year.

U.S. Ambassador Christopher Stevens and three other Americans were killed in the attack on the mission and a nearby annex. In an interview for '60 Minutes,' correspondent Lara Logan spoke with a British citizen, who had been hired to train the Libyan guards at the U.S. mission. He calls himself Morgan Jones, a pseudonym to protect his safety.

Jones says he was annoyed that the State Department wouldn't allow his guards to carry guns. As the attack began on Sept. 11, one of the guards called Jones, who was living nearby.

Benghazi: A timeline of events

'I could hear gunshots, and I -- and he said, 'There's -- there's men coming into the mission,'' Jones said. 'His voice, he was -- he was scared. You could tell he was really scared, and he was running. You could tell he was running.'

His first thought was for his American friends, the State Department agents, pinned down inside the compound, and he couldn't believe it when one of them answered his phone.

'I said, 'What's going on?' He said, 'We're getting attacked.' And I said, 'How many?' And he said, 'They're all over the compound,'' Jones said. 'And -- I was shocked. I didn't know what to say. And I said, 'Well, just keep fighting. I'm on my way.''

Morgan's guards, unarmed and terrified, were surrounded by heavily armed gunmen, but they still sounded the alarm.

'They said, 'We're here to kill Americans, not Libyans,' so they'd give them a good beating, pistol whip them, beat them with their rifles and let them go,' Jones said.

An independent investigation in Benghazi found the mission security was grossly inadequate and that requests for additional security were not approved at State Department headquarters.

You can see Lara Logan's full report, which explains the attack through the eyes of those who understood it best, this Sunday on '60 Minutes.'