On board the Costa Concordia, thousands of passengers were dining, drinking, attending a magic show, perhaps trying their luck in the casino.

It was Friday night on the luxury cruise liner, sailing in the Mediterranean off the Italian coast with about 3,200 passengers and 1,000 crew members -- a night of entertainment and relaxation.

There was annoyance, but no real alarm, when the lights went out -- not at first. Passenger Vivian Shafer said she thought it was part of the magic show.

But those on board then heard an ominous scraping sound, and the 951-foot vessel gave a shudder. The ship began to list to one side.

Still, many passengers were not panicked. Shafer said they were told the problem was electrical and would be fixed soon. Her cabin steward told her there was nothing to worry about. Did this rock cause cruise disaster?

But there was plenty to worry about: the Concordia had struck rocks off Italy's Giglio Island and was taking on water.

As it dawned on them that something was wrong, passengers headed toward the lifeboats -- accessible only on one side of the leaning ship.

According to passengers' accounts, chaos ensued as guests rushed to fill the lifeboats and escape the ship. Some crew members helped passengers and then jumped overboard, passengers said; remaining crew members seemed helpless to handle the melee.

"Women and children first," a lifeboat crew member announced -- meaning families who were clinging to one another had to be separated. Passenger Benji Smith, who was on his honeymoon, made a rope ladder to climb down from the outer fourth deck to the third deck. He and his wife Emily clung to the ladder for more than three hours before they were picked up by a lifeboat.

"You were going higher and higher, and you were on a vertical position," said Rosalyn Rincon, a dancer aboard the ship. "I was holding on to the railing." Noise and creaks could be heard, she said. "It was very, very scary."

Amanda Warrick, on the cruise with her brothers, said she thought several times that she might die. She and her siblings waited for at least an hour and a half for help after all the lifeboats had departed.

"Waiting was definitely the worst," she said. "Because we didn't know who was going to be coming, how much longer we would have to wait."

Crew members were hard to find in the confusion, and little to no information was available about what to do or what was happening, passengers have said. Shafer said she wished the crew had directed passengers to grab warm clothes, coats or shoes, as there was time for them to do so. Authorities said no mayday distress signal was issued by the ship and are investigating.

"The crew tried hard but they kept telling us they had no information," said American Nancy Lofaro. "It wasn't until an hour into this situation that we got into a lifeboat and were lowered."

In the haste, some lifeboats malfunctioned or were not operated properly, some said.

"At one point we were being lowered, and we were sliding off to one side," Lofaro said. "Everyone fell into one side of the boat and were slamming into the ship. This happened a few times over 30 seconds. And finally we were lowered into the water level. It took 30 minutes to get to shore ... the lifeboats were slamming into each other. It was chaos."

Lifeboats on the ship's higher side became stuck, leaving people suspended in mid-air amid the screams and cries of children, said passenger Laurie Willits.

Some passengers braved the water, with a temperature of about 57 degrees, and swam to safety. Others had no choice, as they fell into the chilly water. Nighttime temperatures on Giglio have recently dipped below freezing.

On shore, sirens blared as some of the 20 injured were taken to hospitals. Helicopters plucked some passengers off the ship's decks.