The usual bustle in the streets and sidewalks around New York’s famed Rockefeller Plaza was halted for about an hour this afternoon after an unidentified man scaled the glass wall of the building’s 66th-story observation deck and threatened to jump. Police and fire officials blocked off parts of 5th Avenue and West 50th St. as the man perched on the building’s ledge; he eventually surrendered to authorities, but not before throwing several items to the street below. An NBC producer told the New York Daily News that 30 Rock’s most famous tenant, NBC, had a live feed of the scene showing in one of the network’s newsrooms. “The office was incapable of working once we caught wind of this guy,” he said.