The recovered Sewol ferry is set to leave for a port in Mokpo on Thursday, exactly 1080 days after it left Incheon with 476 people aboard. Though rusted and corroded, the main hull of the 6,800-ton cruiser remains intact and seeing it make its voyage on a transport vessel will remind us of all the shock, frustration, anger and grief we went through nearly three years ago when it sank. 

Officials expect that after its arrival at Mokpo, it will take about five more days before the Sewol is put on land. That should start the long-awaited work to relieve the sorrow of bereaved families of the 304 people who did not make the voyage to Jeju Island on the day of April 16, 2014. The nation, which also suffered, also needs solace and reassurance that there would never be any such disaster again. 

The first thing to do is to find the remains of the nine missing people, which divers and rescue workers failed to recover after months of rigorous underwater operations after the ship sank.

Besides looking into the inside of the wreck, the search in the sea bed on the site of the sinking -- now surrounded by a 3-meter-high net -- should proceed without a hitch. It is the duty of a nation to get all the remains of the victims and their belongings back to their loved ones.

Then they should work at determining the exact cause of the sinking. Past investigations by the state prosecution and a special panel pointed to a set of problems that resulted in the ship sinking in a matter of hours.

Investigators found that the ferry was illegally remodeled in a way to increase the passenger cabins, carried excessive freight -- twice the permitted level -- and even dumped some of its ballast water so it could load more cargo.

Some of the overloaded cargo was not stored properly, which, when the ship made a sharp turn, forced the ship to lose balance and started sinking. 

But there have been persistent rumors and allegations about the direct cause of the disaster. Some raised the possibility of the ship hitting a reef and others said an explosion inside the ship is suspected.

Another ridiculous allegation was that the Sewol collided with a submarine. Some strongly believed in the allegation that a nine-hour documentary produced by a self-claimed civilian investigator made headlines as recently as last December.

But the wreck of the ferry that has been hauled above the water did not have any such mark that would have been made by a major collision with an outside object like a submarine.

Now the work to end such rumors and find the exact cause of the disaster will be left to the eight-member panel tasked to investigate the wreck. It should make a prompt, thorough investigation, and no one should be allowed to interfere with their activities. 

The Sewol sinking exposed so many ills that laid the basis for the worst disaster in the nation’s maritime history: the ferry operator had long disregarded safety rules in pursuit of profit, regulators were either corrupt or negligent, maritime police were not adequately prepared for rescue operations and the captain and his crew abandoned their professional duty by escaping the ship before their passengers which included many high school students.

The salvage of the Sewol ferry should serve as a fresh reminder that those and other problems in this society have yet to be addressed properly, and there still is a long road before enhancing the level of a safety system in the country.

It is also hoped that the tragedy and the upcoming investigation of the wreck do not become the source of a new political and social conflict. Most of all, politicians, especially presidential hopefuls, must not try to exploit the issue to their advantage.