BRANSON, Mo. — Seventeen people, including at least one child, are dead after an amphibious duck boat capsized Thursday evening on Table Rock Lake in Branson, Missouri.

Among the passengers was an 11-member family, nine of whom died, according to Gov. Mike Parson's office.

At least seven other passengers were injured, including two in serious condition. On Friday morning, the Missouri State Highway Patrol found the last four bodies that had been unaccounted for, according to Stone County Sheriff Doug Rader.

Rader reported 11 people were dead just after 11 p.m. Thursday. Two more bodies were discovered later in the night before the final search on Friday. The Ride the Ducks tourist boat sank near the Showboat Branson Belle with a reported 31 people on board.

During a press conference Friday morning, Rader said it was too early to know the cause of the incident. He said there were life jackets in the boat, but it's not clear how safety equipment was used.

Rader said the investigation is ongoing and added, "It's been a very trying night."

He said the captain of the boat, who has 16 years of experience, survived, but the driver did not. Rader declined to give an age range of the passengers or elaborate on whether they were local or tourists.

“We’re still working with families and making notifications, so at this time, I’m not giving that information out,” he said.

He said it is unknown whether the captain or Ride the Ducks staff checked the forecast prior to going on the lake. He said he has not spoken to the survivors yet.

He asked that anyone who has video of the incident send it to his office to help with the investigation.

Missouri Governor Mike Parson thanked first responders, volunteers and dive teams during a press conference on Friday morning. "Our thoughts and prayers are with the families and the victims in this tragic event that's occurred down here," said Parson.

Parson committed all state resources to help in the investigation. Both the Coast Guard and National Transportation Safety Board are assisting.

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Guain Holloman, of Tennessee, places a flower on the windshield of a car in the Ride the Ducks parking lot in Branson on Friday.
Andrew Jansen/News-Leader

Passengers on a nearby boat told ABC's "Good Morning America" that the water became rough as the wind picked up.

"Debris was flying everywhere," Allison Lester said in an interview Friday.

Lester's boyfriend, Trent Behr, said they saw the body of a woman in the water and helped to pull her into the boat. He said he was about to start CPR when an EMT arrived and took over.

A spokeswoman for the Cox Medical Center Branson said four adults and three children arrived at the hospital shortly after the incident. Two adults are in critical condition and the others were treated for minor injuries, Brandei Clifton said.

Steve Lindenberg, a National Weather Service meteorologist in Springfield, Missouri, said the agency issued a severe thunderstorm warning for the Branson area Thursday evening. Lindenberg said winds reached speeds of more than 60 mph (100 kph).

Capt. Jim Pulley, owner of Sea Tow Table Rock Lake, told the Springfield News-Leader that the winds pushed the duck boat that capsized behind a steamboat that was tied to the dock.

Rader said an off-duty sheriff's deputy working security for the boat company helped rescue people after the boat capsized. Dive teams from several law enforcement agencies assisted in the effort.

President Donald Trump tweeted his condolences Friday, extending his deepest sympathies to the families and friends of those involved.

Suzanne Smagala with Ripley Entertainment, which owns Ride the Ducks in Branson, said the company was assisting authorities with the rescue effort. Smagala added this was the Branson tour's only accident in more than 40 years of operation.

Branson is about 200 miles (320 kilometers) southeast of Kansas City and is a popular vacation spot for families and other tourists looking for entertainment ranging from theme parks to live music. An EF2 tornado that bounced through downtown Branson in 2012 destroyed dozens of buildings and injured about three dozen people, but killed no one.

Duck boats, which can travel on land and in water, have been involved in other deadly incidents in the past. Five college students were killed in 2015 in Seattle when a duck boat collided with a bus; the operation in Branson is separate from Seattle. Thirteen people died in 1999 when a duck boat sank near Hot Springs, Arkansas.

Safety advocates have sought improvements since the Arkansas deaths. Critics argued that part of the problem is that too many agencies regulate the boats with varying safety requirements.

Duck boats were originally used by the U.S. military in World War II to transport troops and supplies, and later were modified for use as sightseeing vehicles.

Contributing: Associated Press