It's Almost Time To Flip The Shipwrecked Costa Concordia - Here's How The Complex Plan Will Go Down

It's been more than a year since the cruise ship Costa Concordia struck a reef off the shore of Isola del Giglio, in the Mediterranean, leading to a wreck that cost 30 passengers their lives.

Yet the enormous ship is still sitting off the Italian coast, mostly submerged, in the middle of a nationally protected marine park and coral reef.

The ingenious salvage operation -called the "Parbuckling Project" - involves building a series of underwater platforms onto which the Costa Concordia will be lifted upright (parbuckled), then floated up and towed away.

Nearly all the preparations have been completed, and the crucial phase of the plan - the parbuckling itself - is about to go down: Italian regulators have greenlighted the operation for this month.

The teams on site will have only one chance to flip the ship upright. If it goes wrong, the backup plan is to break up the ship where it lies, at a huge cost to the local environment.

Here's what's happened so far, and how the teams hope it will go.