At the Italian port of Civitavecchia, 40 miles northwest of Rome, the great cruise ships line the long concrete breakwater like taxis at a curb. That Friday afternoon, January 13, 2012, the largest and grandest was the Costa Concordia, 17 decks high, a floating pleasure palace the length of three football fields. It was a cool, bright day as the crowds filed on and off the ship, those who had boarded at Barcelona and Marseilles heading into Rome for sightseeing while hundreds of new passengers pulled rolling bags toward the *Concordia’*s arrival terminal.

Up on the road, a writer from Rome named Patrizia Perilli stepped from a chauffeur-driven Mercedes and marveled at the ship’s immensity. “You could see it even before you entered the port; it was a floating monster,” she recalls. “Its size made me feel secure. It was sunny, and its windows were just sparkling.”

Inside the terminal, newcomers handed their luggage to the Indian and Filipino pursers. There was a welcome desk for an Italian reality show, Professione LookMaker, filming on board that week; among those arriving were 200 or so hairdressers from Naples and Bologna and Milan, all hoping to make it onto the show. As they chattered, flashed their passports, and boarded, then slowly filtered throughout the ship, they thought it all grand: 1,500 luxury cabins, six restaurants, 13 bars, the two-story Samsara Spa and fitness center, the three-story Atene Theatre, four swimming pools, the Barcellona Casino, the Lisbona Disco, even an Internet café, all wrapped around a dramatic, nine-story central atrium, itself a riot of pink, blue, and green lights.

Some of the hundred or so Americans on board weren’t so wowed. One likened wandering the Concordia to getting lost inside a pinball machine. “It kind of reminded me of old Vegas, you know?” says Benji Smith, a 34-year-old Massachusetts honeymooner, who had boarded at Barcelona with his wife, along with two of her relatives and two of their friends, all from Hong Kong. “Everything was really gaudy, lots of fancy blown glass in different colors. The entertainment kind of reinforced the old-Vegas thing, aging singers performing solo on a keyboard with a drum track.”

There were just over 4,200 people aboard the Concordia as it eased away from the breakwater that evening, about a thousand crew members and 3,200 passengers, including nearly a thousand Italians, hundreds of French, British, Russians, and Germans, even a few dozen from Argentina and Peru. Up on Deck 10, Patrizia Perilli stepped onto her balcony and daydreamed about sunbathing. As she began to unpack in her elegant stateroom, she glanced over at her boyfriend, who was watching a video on what to do if they needed to abandon ship. Perilli teased him, “What would we ever need that for?”

As the world now knows, they needed it desperately. Six hours later the Concordia would be lying on its side in the sea, freezing water surging up the same carpeted hallways that hairdressers and newlyweds were already using to head to dinner. Of the 4,200 people on board, 32 would be dead by dawn.

The wreck of the Costa Concordia is many things to many people. To Italians, who dominated the ship’s officer ranks and made up a third of its passengers, it is a national embarrassment; once the pinnacle of Mediterranean hedonism, the Concordia was now sprawled dead on the rocks in a cold winter sea.

But the *Concordia’*s loss is also a landmark moment in naval history. It is the largest passenger ship ever wrecked. The 4,000 people who fled its slippery decks—nearly twice as many as were aboard the R.M.S. Titanic in 1912—represent the largest maritime evacuation in history. A story of heroism and disgrace, it is also, in the mistakes of its captain and certain officers, a tale of monumental human folly.