The salvage operation is expected to cost $400 million (insurance companies are footing the bill).
After the wreck, workers raced to secure the ship. They worked around the clock, 24 hours a day and 7 days a week.
111 salvage divers worked underwater, going around the clock in 45-minute shifts.
One of the biggest dangers has been weather: The ship is held in place by steel cables, but it could be dislodged by a strong storm. It's now sitting on two underwater mountain peaks. If it sinks, salvaging it would be nearly impossible.
next slide will load in 15 secondsSkip AdSkip AdFortunately, tests have shown no alterations of the water around the site, which remains as clean as it was before the wreck.
The plan is to flip the ship upright, then tow it away.
But right now, it's filled with seawater so it won't float. To create buoyancy, the teams are welding enormous, hollow steel boxes onto each side of the ship.
They started with the exposed side. Before beginning, workers had to take a four-day mountain climbing course.
They also attached steel cables that will be used to pull the ship upright.
next slide will load in 15 secondsSkip AdSkip AdThe next, crucial step is the parbuckling itself. The ship will be rotated using hydraulic pulleys.
Once this process begins, it can't be stopped, even if something goes wrong. It will take several days.
If all goes well, the Costa Concordia will come to rest on a huge underwater platform built for the operation.
All of the steel used in the platform will weigh 3 times as much as the Eiffel Tower.
The platforms are embedded in holes drilled in the seafloor.
next slide will load in 15 secondsSkip AdSkip AdAfter the parbuckling, more of the hollow boxes (called sponsons) will be welded onto the other side of the ship.
The sponsons should add enough buoyancy to make the ship float.
Then the defunct cruise liner can be towed away and cut up for scrap — a process that's expected to last two years.
If the parbuckling goes wrong, the backup plan is to break up the ship where it lies, and likely damage the sensitive local environment.