"A security guard who called 911 after a gunman entered Discovery Channel's headquarters calmly told the operator: ""You're probably going to need a sniper."" The call, released Friday, was one of several placed minutes after a gunman entered the lobby and took three hostages. Other callers described the propane tanks strapped to the gunman's body, and a blinking device in his left hand. After hours of negotiating with James Lee, 43, police shot him to death as the hostages were preparing to make a break for it, police said. Even in the first minutes after the siege began, Discovery security had an idea of who they were dealing with. A security employee told a 911 operator that they believed the man was in the lobby was Lee. He told the operator Lee appeared disoriented, had propane tanks strapped to his chest and at least one person on the ground. ""It looks like he's got an IED. He looks like he's setting up an explosive device in the lobby, you're probably going to need a sniper,"" he tells the operator. ""You gotta move fast."""