Survivors of the Costa Concordia shipwreck and relatives of the 32 people who died marked the first anniversary of the grounding yesterday with the unveiling of memorials to the victims, a Mass in their honour and a minute's silence to recall the moment the cruise ship rammed into a reef off Tuscany.

The day's events saw the return to the sea of part of the massive rock that tore a 230ft gash in the hull of the ocean liner on January 13, 2012. The boulder remained embedded in the mangled steel as the 112,000-ton vessel capsized along with its 4200 passengers and crew.

As fog horns wailed, a crane on a tug lowered the boulder onto the reef off Giglio, returning it to where it belongs and affixed with a memorial plaque. Relatives threw flowers into the sea and embraced as they watched the ceremony from a special ferry that bobbed under a slate gray sky.

The Costa's captain, Francesco Schettino, is accused of multiple manslaughter, causing a shipwreck and leaving the ship before all passengers were evacuated.