The well-crafted paragraph

It's been eight years since I read The Secret History but this paragraph still strikes me as the epitome of style.

Hampden College, as a body, was always strangely prone to hysteria. Whether from isolation, malice, or simple boredom, people there were far more credulous and excitable than educated people are generally believed to be, and this hermetic, overheated atmosphere made it a thriving black petri dish of melodrama and distortion. I remember well, for instance, the blind animal terror which ensued when some townie set off the civil defense sirens as a joke. Someone said it was a nuclear attack; TV and radio reception, never good there in the mountains, happened to be particularly bad that night, and in the ensuing stampede for the telephones, the switchboard shorted out, plunging the school into a violent and almost unimaginable panic. Cars collided in the parking lot. People screamed, wept, gave away their possessions, huddled in small groups for comfort and warmth. Some hippies baracaded themselves in the Science Building, in the lone bomb shelter, and refused to let anyone in who didn't know the words to "Sugar Magnolia". Factions formed, leaders rose from the chaos. Though the world, in fact, was not destroyed, everyone had a marvelous time and people spoke fondly of the event for years afterward.

--The Secret History, Donna Tartt, Chapter 7

Factions formed, leaders rose from the chaos. A golden line in context. It's become a catchphrase here.