As employees huddled in offices or escaped to a nearby McDonald's, Jim McNulty and Chris Wood were trapped in the lobby of the Silver Spring, Md., Discovery Channel headquarters along with a security guard and disgruntled environmentalist James Lee.
Lee, who had walked into the company headquarters shortly after 1 p.m. Sept. 1, was carrying a gun -- later determined to be a starter pistol -- and wearing bombs strapped to his body. He was furious about what he believed to be the over-population of humans that is damaging the environment.
Believing their time could be running out, Wood said he made the decision to bolt. "I was not going to die there," he said. "I was not going to die on that floor.
"I mouthed to the guard we need to run and he nodded his head yes," Wood said.
He got McNulty's attention and when McNulty nodded his head in agreement, Wood began counting down using his fingers, out of Lee's sight. But when he got down to one, Lee was looking right at him.
"As soon as he looked down ... I ran," Wood said.
The hostages said they've since replayed their escape "over and over."
After running to safety and finding his family waiting for him, McNulty picked up his daughter and hugged her tightly.
"My daughter said, 'Dad let go,'" he said. "I said, 'Uh-uh -- not going to.'"
Lee, who was arrested in 2008 after protesting Discovery, had apparently shown up at headquarters to force people to listen to his ideas that humans were the scourge of the earth.
McNulty said he had been quietly lying on the floor when Lee suddenly began questioning him.
"He said, 'You in the glasses, stand up. I stood up with my hands up," he said.
When Lee questioned him about his job, McNulty, a producer, told him he worked in scheduling. "I didn't want to become part of what his problem was," he said.
But then the conversation shifted to McNulty's children.
"Who told you to have kids?" McNulty said Lee shot back. "'You're going to have them sterilized right?' I'm like 'I'll tell them your thoughts on that.'"
That's when Lee began ranting and raving about McNulty's "filthy" children.
While McNulty was walking on eggshells around the man the hostages believed would kill them, Wood was discreetly using his phone to text and e-mail.
"I'm being held hostage in the lobby," he sent to a coworker, followed by a message for his partner. "Please tell Mark I love him."
A lengthy manifesto posted on Lee's website rants about "disgusting human babies," "parasitic infants" and says people should "disassemble civilization."
The manifesto also called on Discovery to "broadcast to the world their commitment to save the planet."
Communicating with authorities that had surrounded the building, Lee said, "I have a gun and I have a bomb. I have several bombs strapped to my body ready to go off."
Lee was eventually shot and killed after authorities stormed the lobby.
Montgomery County Police Chief Thomas Manger told ABC News that Lee had unleashed his terror with one goal in mind.
"My sense from listening to him was that he had no intention of leaving alive," he said shortly after the incident.