Duck boats like the one that sank in Branson, Missouri, killing 17 people, have a long history of safety problems and have been linked to the deaths of more than 40 people since 1999.
The deadly sinking in Missouri brought back painful memories of a similar accident nearly two decades ago in Arkansas.
Both duck boats had overhead roofs or canopies that the National Transportation Safety Board warned could greatly increase the risk of passengers becoming trapped in the boat and drowning.
The sinking on Table Rock Lake near Branson Thursday came during stormy weather. The official cause has not been determined, but investigators initially blamed thunderstorms and winds that the National Weather Service clocked at 65 miles per hour (105 kph).
On May 1, 1999, 13 people died when the Miss Majestic duck boat sank on lake Hamilton near Hot Springs, Arkansas. The NTSB's report on that accident found that roofs or canopies on duck boats greatly endanger passengers in the event of a sinking. The report said that passengers — because of their natural buoyancy, especially if they are wearing life jackets — can become trapped against the canopy as the vessel sinks, unable to swim down to openings along the side.
Video of the duck boat in Branson just before it sank shows it not only had a roof, but windows, which some companies have added to their vessels so they can heat the cabin and extend their hours, said Robert Mongeluzzi, a Philadelphia attorney who represented families of two victims killed when a barge plowed into a stalled duck boat in the Delaware River in 2010.
"You need to get out of a sinking coffin with tons of water pouring in," Mongeluzzi said. "Your chances of escape are not good."
After the sinking in Arkansas, the NTSB recommended that the industry remove canopies from the vessels.
"If the vehicle had not had a canopy, the passengers would not have had a barrier to vertical escape. They would not have been trapped inside the vehicle, and fewer passengers might have been killed," the report said.
General Motors developed the DUKW in 1942 to get supplies and reinforcements to World War II troops, and the amphibious vehicles became known as "ducks." They were later modified for use for sightseeing in cities around the U.S. The long, narrow vehicles are shaped like boats, but have wheels they use when on land.
Safety advocates have sought improvements and complained that too many agencies regulate the boats with varying safety requirements.
Here are details on some fatal duck boat accidents and the conclusions reached by investigators about safety violations and needed improvements:
Sept. 24, 2015: Five college students were killed and more than 70 people injured when a duck boat veered into a charter bus on a bridge above Seattle's Lake Union. The National Highway Traffic Safety Administration determined that the front axle on the boat broke, causing the driver to lose control. The vehicle had not had a recommended repair designed to prevent axle failure. Ride the Ducks of Seattle stopped using older "stretch ducks" after the accident and now only uses newer "truck ducks." The company said it also added 365-degree video coverage and a second employee to narrate tours.
July 7, 2010: A collision on the Delaware River near Philadelphia between a stalled duck boat and a tug-boat guided barge sank the sightseeing boat, killing two Hungarian tourists and injuring more than 25 people. The NTSB found that the tugboat operator was distracted by communicating with family members on his cellphone and laptop computer. Investigators also found fault with the maintenance of the duck boat and decisions by the captain to anchor in an active navigation channel.
May 8, 2015: A duck boat struck and killed 68-year-old Elizabeth Karnicki of Beaumont, Texas, as she crossed a busy Philadelphia street at rush hour. A police spokeswoman said witnesses reported that Karnicki was looking at an electronic device while walking and crossed the street against the red light when she was hit.
July 16, 2003: Sixty-three-year-old Rosemary Hamelburg fell backward off a duck boat onto a parking lot while taking a photo and died four days later. In a wrongful death lawsuit, her family and lawyers alleged that duck boat operators contributed to the death by failing to follow their own safety policies for the boarding and pre-departure process. Boston Duck Tours paid $425,000 to Hamelburg's estate to settle the suit.
April 30, 2016: A duck boat ran over and killed 28-year-old Allison Warmuth as she rode on a motor scooter. Video examined by the NTSB showed the driver taking his eyes off the road and turning in his seat to point out landmarks during the tour. The accident prompted the state Legislature in Massachusetts to pass a law that now prohibits duck boat drivers from simultaneously serving as narrator and tour guide. The law also requires duck boats to be equipped with blind spot cameras and proximity sensors.
Sept. 17, 2007: A California woman died in Ketchikan, Alaska, when a duck boat hit her as she was walking on a dock. Myong S. Thayer, 59, died on the scene after the duck boat ran into her on a dock shared by vehicles and pedestrians. The driver of the vehicle was not charged.
HOT SPRINGS, ARKANSAS
May 1, 1999: A duck boat sank on Lake Hamilton near Hot Springs, Arkansas, killing 13 people. The NTSB blamed the sinking on inadequate maintenance. Investigators determined that the vessel, built by the Army in 1944, was not designed for passenger service. As a result, it did not have the proper buoyancy to remain afloat.
Associated Press writers Eugene Johnson in Seattle and Jennifer Farrar in New York contributed to this report.