Four months after a duck boat sank on Table Rock Lake, killing 17 people, federal prosecutors announced Thursday the captain of the vessel has been indicted on criminal charges.

Tim Garrison, United States Attorney for the Western District of Missouri, held a news conference Thursday morning to announce the charges against 51-year-old Kenneth Scott McKee.

Officials say McKee was operating Stretch Duck 7 when the amphibious vessel sank on July 19 with 31 people on board during a thunderstorm on the lake.

For each of the 17 people who died, a federal grand jury indicted McKee on counts of misconduct, negligence, or inattention to duty by a ship's officer, resulting in the death of another.

Garrison said the charges are colloquially known as "seaman's manslaughter" and that McKee's indictment was the "first" related to the duck boat tragedy.

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It's unclear if more indictments are coming against other people.

"This indictment represents the beginning, and not the end, of our efforts in this matter," Garrison told reporters. He declined to comment on other possible indictments but said the investigation is ongoing.

The allegations against McKee are that he failed to properly assess incoming weather that July evening and then missed opportunities to either help passengers escape or get the boat back to shore safely. McKee's actions, prosecutors allege, contributed to or caused the deaths of 17 people.

Prosecutors say there was lightning in the area of Table Rock Lake when McKee drove the duck boat into the water.

During the fatal voyage, prosecutors say McKee failed to tell passengers to put on their personal flotation devices and also failed to raise the boat's side curtains as it took on water. Attorneys have alleged the side curtains, in addition to the boat's canopy, trapped passengers inside the vessel as it sank.

If convicted, McKee could face 10 years in prison on each of the 17 counts, prosecutors say.

Garrison said Thursday morning that McKee was not in custody, but he would be surrendering soon. Garrison declined to say whether McKee cooperated with the U.S. Attorney's Office's investigation.

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McKee's attorney, J.R. Hobbs, said Thursday that he expected McKee to make his first court appearance next week and plead not guilty. Hobbs declined to comment further on the allegations.

Ripley Entertainment, which operates the Branson Ride the Ducks operation, in addition to Ride the Ducks International, have also been sued by many survivors of the sinking and family members of the deceased.

Those lawsuits are making their way through the court system. The U.S. Attorney's Office had asked to delay some proceedings in the lawsuits as they continued their criminal investigation.

In the lawsuits, attorneys claim the duck boat operators were negligent in ignoring weather warnings and not heeding calls to change the design of the boats after a similar tragedy in 1999 in Hot Springs, Arkansas.

The main source of debate on the civil side of things is whether Table Rock Lake is a "navigable waterway."

If a judge in the civil cases determines that it is, then Ripley Entertainment could make their case that the 1851 Shipowner's Limitation of Liability Act applies, and damages for plaintiffs would be capped at no more than the value of the sunken vessel — which is zero dollars.

As part of their criminal indictment on Thursday, federal prosecutors allege that Table Rock Lake is a navigable water "within the admiralty jurisdiction of the United States."

Garrison explained that this determination gives the federal government jurisdiction to prosecute the case, but he declined to comment on any impact this might have on the civil lawsuits.

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Garrison was also pressed Thursday on whether McKee was culpable or just following orders.

According to the National Transportation Safety Board, someone stepped onto the duck boat before it departed on its July 19 trip and advised McKee to take the water portion of the tour first after a discussion about incoming weather.

Garrison was asked Thursday if that unidentified person is under investigation.

Garrison declined to comment but added that a captain is responsible for his vessel under federal law.

“The captain of the vessel always has a duty to operate his vessel in a safe manner, that’s why Mr. McKee is under indictment this morning,” Garrison said.

Of the 17 people who died, nine were members of the same Indiana family.

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Robert Mongeluzzi, whose law firm represents survivor Tia Coleman and others, applauded the U.S. Attorney's Office on Thursday for its "methodical and laser-focused investigative work."

"We are confident that further investigation will reveal that the failures which led to this tragedy go far beyond the role of a single duck-boat captain and implicate others in the Ripley's entertainment empire," Mongeluzzi said in a statement.