Storm-driven waves broke open the bow door of the ferry Estonia, letting in water that caused the ship to roll over and sink, the head of Sweden's maritime safety division said Friday.
Bengt Erik Stenmark also told reporters that another popular Baltic Sea ferry, the Mariella, was barred from leaving Stockholm harbor because of problems with the monitoring system for its bow door.Stenmark said the Estonia's "bow door had a break . . . and was exposed to the excessive forces of the sea" before it sank off Finland's southwestern coast Wednesday, killing more than 900 people in Scandinavia's worst maritime disaster.
"One man saw the ship sinking without the bow section, and another was walking in knee-high water on the car deck," Stenmark said.
He said an "intelligent guess," based on those witness reports, was that waves could have widened a gap in the bow door, allowing water in and causing the ship to lose stability.
Cars and trucks are loaded on or off through bow and stern doors.
Whether the door was ripped off completely or not, the ship would have sunk, because a relatively small amount of water in the cargo deck can destabilize a ferry.
Stenmark was quoted as saying at a news conference that two witnesses saw the bow door missing when the Estonia sank, but he clarified at a second news conference that only one witness reported that.
He said one witness watched water quickly build up to 12 to 20 inches in the car deck before the ferry sank. "In such a situation, everything is already lost," Stenmark said.
At the rescue operations center in Finland, experts questioned Stenmark's state-ment.
"It's a theory, one of the theories," said Tuomo Karppinen, a member of the official inquiry board into the accident. He said no conclusions could be reached so far based only on witnesses' accounts.
Salvage workers set out Friday hoping to use sophisticated sonar to locate the Estonia on the Baltic floor. They then planned to send down a robot to look at the wreck, located in water about 260 feet deep.
Spurred by reports of safety problems that emerged after the disaster, Swedish investigators fanned out to popular passenger ferries today to check bow doors and other ship features.
As a result, the Mariella was blocked from sailing, Stenmark said. That ship was one of several ferries that helped rescue survivors from the Estonia.
On Thursday, Stenmark said shipping companies had called to report earlier incidents in which bow doors came loose or did not close properly, letting water onto vehicle decks.