Duck boat companies have had a string of bad luck -- and fatal accidents. And not just in Philadelphia, where Ride the Ducks International ceased operations Wednesday.
In Seattle, a duck boat collided with a charter bus on Seattle's Aurora Bridge in September 2015, killing five people and injuring many others.
In Boston, a 28-year-old woman was killed in April by a Boston Duck Tours vehicle while riding her scooter in Beacon Hill.
Ride the Ducks shut down Philadelphia operations "indefinitely" this week, citing soaring insurance costs.
In a statement on its website, the company said: "Due to circumstances outside of our control, including a 330 percent increase in our insurance premiums, continued operations in Philadelphia are not financially feasible."
Ride the Ducks International, based in Branson, Mo., did not return phone calls Thursday about whether operations in other cities would also be shuttered.
"Let's assume that we are only talking about the operations in Philadelphia," said Temple University insurance professor R.B. Drennan. "I suspect the liability insurance is what's driving this."
Ride the Ducks Philadelphia has had "huge wrongful-death losses" -- three people killed since 2010, said Drennan, who chairs the risk, insurance and healthcare management department at Temple's Fox School of Business.
"If I am an insurer, and this is one of my customers, do I really want to insure this enterprise? The answer is probably no," he said. 'The insurer's way of telling them, 'Hey, we don't want you as a customer anymore,' is to raise their insurance premium 330 percent."
In May 2015, a duck boat struck and killed a Texas woman who was crossing the street at 11th and Arch Streets in Philadelphia's Chinatown.
In July 2010, two Hungarian students were killed when a tugboat struck a duck boat on the Delaware River. The tug operator, who was talking on his cellphone at the time, was sentenced to a year and a day in federal prison. The duck boats did not operate in Philadelphia for eight months.
Robert J. Mongeluzzi, whose firm won $17 million for the families of the tourists killed and passengers in the 2010 accident, said that duck boats are "dangerous on the land and in the water" and that it was good news they are gone.
Philadelphia's fleet of 20 to 25 duck boats have been involved in three fatalities in five years, he said. "If you compare those rates to the number of fatalities per mile driven in a passenger car, you are talking about rates of fatalities literally thousands of times higher."
"If there is any question about why their insurance rates have increased, it is because they continue to kill people," Mongeluzzi said. "This history of death goes back decades, starting with Miss Majestic in Arkansas, where 13 drowned in 1999."
The design of the water-to-land vehicles, he said, is flawed. "They are death traps, and the insurance rates accurately capture the danger," Mongeluzzi said.
The duck boats on land are wider than a city traffic lane. They have built-in blind spots because a bow in front extends six to eight feet, blocking the view of pedestrians, he said.
Chris Davis, a Seattle attorney representing two passengers in a fatal duck boat accident on the Aurora Bridge last year, said the amphibious vehicles are "less safe" than typical commercial vehicles and "come with challenges, especially when driving in city streets."
"They ride so high up on the ground there is a visibility issue," Davis said.
"It can be very difficult to see people when you are that high up off the ground, approaching an intersection," Davis said. "They also take up an enormous amount of space on the road. The incident involving the Aurora Bridge, the lanes are fairly close together. Just one inattentive action by the driver, and just barely going over the center line, caused a massive fatal collision."
In the Seattle crash, an axle on the duck boat broke, and it veered over the center line into a lane of oncoming traffic, striking the bus.
"They are unwieldy, they have blind spots," Mongeluzzi said. "On the water, going back to the Miss Majestic, people drowned because that duck boat had a canopy. If you put on your life preserver, and you are inside and the boat begins to sink, you can't get out the window and you drown."