Choppy seas forced a temporary evacuation of the stricken 17-deck Costa Concordia for several hours after the half-submerged ship slipped on a rocky shelf under the sea, sparking fears that the giant hulk could sink entirely.
Emergency workers said at least 15 people were still missing, including American, French, German and Italian tourists. The death toll also rose to six after the body of a man was found by divers in the early hours of Monday.
"The conditions inside are disastrous. It's very difficult. The corridors are cluttered and it's hard for the divers to swim through," Rodolfo Raiteri, head of the coastguard's diving team told AFP on the shore. Three of the victims -- two Frenchmen and one Peruvian crew member -- drowned after jumping into the chilly winter Mediterranean waters along with dozens of others in a chaotic evacuation in the Friday the 13th tragedy.
Survivors returned home with harrowing accounts of panic on board. The local mayor voiced hope of finding more people alive, but also warned that the stricken vessel, which hit rocks and keeled over off Giglio island, was an "ecological timebomb" in the pristine waters of a marine nature reserve. "You never know in the labyrinth of that ship.
An air pocket could have allowed people to survive a few days mayor," Sergio Ortelli told AFP. The head of the company which owns the monster vessel said it had hit a rock as a result of an "inexplicable" error by the captain, Francesco Schettino, who was arrested on Saturday along with first officer Ciro Ambrosio.