ROME — The captain of the cruise ship that capsized off Tuscany made an unauthorized, unapproved deviation from its programmed course, a “human error” that led to the grounding of the vessel, the chief executive of the ship's Italian owner said today. At least six people died in the incident.

The comments from Costa Crociere chairman and CEO Pier Luigi Foschi ramped up the pressure on the captain, who already is under investigation by authorities for suspected manslaughter and as well as allegations he abandoned ship before the passengers were safe, violating the Italian navigation code.

The Costa Concordia ran into a reef Friday night and capsized into the port area of Giglio, sparking a frantic evacuation of the 4,200 people onboard. Coast Guard officials have expressed concern that the ship might slip off the rocks where it is currently perched.

Today, the rescue operation was called off as weather worsened and a sixth body was found. Foschi said it wasn't because the ship had shifted but because divers heard “sounds” coming from inside and didn't know what was causing them. Sixteen people remain missing.