Mark and Sarah Plath of Little Rock, Ark., awoke to an announcement just before 11 p.m. saying there was a power outage but not to worry about it. Using their iPhone's level app, the couple soon discovered the ship was tilting 23 degrees. When they went outside, they found about 500 people on the fourth floor deck.
"We were trying to get outside," Mark Plath told ABC News. "People had children with them, people were pushing, people were yelling, people were pushing back. It was difficult to stay in control because so many people were upset."
"We were moving really fast and so Mark said, 'We've got to jump,'" Sarah Plath said. The couple jumped and swam to nearby rocks.
Lynn Kaelin of Seattle told ABC News the ship's hallways were so crowded "We couldn't see where we were going. People were crying and screaming. No one was telling us what to do, at all."
Karen Kois, also of Seattle, said she knew to get warm clothing, although others were barefoot and lightly dressed.
"I had a sweater on under a raincoat. I gave it to a baby who had nothing," she said.
As for the pushing and shoving, Kois said, the crew "told us go one way, then the other. We didn't know what to do. They were just standing looking at us."
When they succeeded in reaching a life boat, it took 45 minutes to launch it, with the ropes tangled and the little crafts tilted.
"And it's pitched black," Kois added.
Above them was the clatter of helicopters trying to pluck people from the decks.
"Have you seen 'Titanic?' That's exactly what it was," said Valerie Ananias, 31, a schoolteacher from Los Angeles. She and sister and parents all had dark red bruises on their knees from crawling along nearly vertical hallways and stairwells to reach rescue boats.
"We were crawling up a hallway, in the dark, with only the light from the life vest strobe flashing," her mother, Georgia Ananias, 61 said. "We could hear plates and dishes crashing, people slamming against walls."
She said an Argentine couple handed her their 3-year-old daughter, unable to keep their balance as the ship lurched to the side and the family found themselves standing on a wall.
"He said 'take my baby,'" Georgia Ananias said, covering her mouth with her hand as she teared up. "I grabbed the baby. But then I was being pushed down. I didn't want the baby to fall down the stairs. I gave the baby back. I couldn't hold her."
Giuseppe Romano, a 57-year-old Carabinieri on the cruise, said, "We lived apocalyptic scenes. There was a strident sound followed by a bang and plates and glasses started flying in the restaurant."
"After the first bang, the crew members said there was a fault and that we should stay calm... Then we heard another bang and I think that the ship hit the rocks again. Then the lights went out," Romano said.
"An officer on the ship asked me to help the people. Immediately afterwards I with other men started taking people off the ship. During this whole apocalyptic scene we saw few crew members," he said.
Mike van Dijk, a 54-year-old from Pretoria, South Africa, said crew members delayed lowering the lifeboats even though the ship was listing badly.
"We had to scream at the controllers to release the boats from the side," van Dijk said. "We were standing in the corridors and they weren't allowing us to get onto the boats. It was a scramble, an absolute scramble."
The ship's owner was as mystified by the crash as the passengers.
"At the time of the collision with the rock the captain of the Costa Concordia was on the command bridge," said the Director General of Costa Crociera Gianni Onorato speaking to journalists at the port of Porto Santo Stefano.
Onorato said the liner was on its regular, weekly route when it struck a reef.
"The ship was doing what it does 52 times a year, going along the route between Civitavecchia and Savona," Onorato said.
ABC News' Michael S. James, Mark Mooney and Katie Moisse, and The Associated Press contributed to this report.