With 29 people still missing following the wreck of the Costa Concordia, rescuers in Italy have restarted their search for survivors. On Tuesday, navy divers blew a hole in the ship's hull using small explosive charges and made their way into the submerged vessel.

The charges were placed in areas where it looked like it was easier to find people, and from where it is easier for rescuers to get in and possibly leave the ship in a rush, if it moves again, Italian Navy diver Sergeant Antonino Ruggero stated.

The Costa Concordia sunk on Friday night after captain Francesco Schettino made an unapproved, unauthorized change of course, leading the ship toward the Tuscan island of Giglio, according to Carnival, the company which owns the ship. The boat ran aground and rocks tore a 160-foot hole in the hull.

As the ship began to tilt and fill with water, the Coast Guard began a frantic evacuation of its 4,200 passengers. Nearly all on board disembarked safely, but at least six were killed.

Those still missing include 25 passengers -- including a group of German tourists, six Italians and two Americans -- and four crew members. The Americans have been identified as Jerry and Barbara Heil from White Bear Lake, Minn., according to USA Today.

The Italian Coast Guard still has a glimmer of hope that the missing will be found alive somewhere in the ship. There are still cabins and rooms that were not fully submerged.

Environmental Concerns

Italy called a state of emergency late on Monday over fears that rough seas could shift the Concordia and send its 500,000 gallons of fuel into the waters of Giglio, which have in the past been praised as the cleanest and clearest in all of Italy.

Oil removal ships watched the massive cruise-liner throughout the night, and so far there have been no reports of any leaks. But with shifting seas on Monday, there is again fear that the vessel could be pushed into rocks that would rupture the fuel tanks.

Costa Crociere SpA , which operated the stricken vessel, has contracted Smit of Rotterdam, one of the world's top salvaging companies, for the safe removal of the liner and its fuel.