The family of the pedestrian killed by a Ride the Ducks vehicle in May filed a lawsuit Tuesday against the tour boat's operator, its manufacturer, and the city of Philadelphia.

The complaint alleges that the accident that killed Elizabeth Karnicki, 68, at the intersection of 11th and Arch Streets on May 10 was due in part to "huge blind spots" inherent in the amphibious vehicles that operate on city streets and on the water.

The suit came on the fifth anniversary of the fatal duck boat accident that killed two Hungarian tourists when the vehicle collided with a barge on the Delaware River.

Lawyer Robert J. Mongeluzzi, whose firm won $17 million for the families in the 2010 crash, said the popular vehicles are, "clearly a lethal threat to pedestrians." He called for all duck boats to be removed from Philadelphia streets.

What makes these boats so dangerous on land, he said, is the position of the driver, who sits 10 feet back from the nose of the boat-shaped vehicle.

Drivers are also challenged, Mongeluzzi said, by the double-duty of driving and entertaining an audience on busy, crowded streets.

Ride the Ducks International LLC, the parent company based in Atlanta, said in a statement Tuesday that the driver of the vehicle that struck Karnicki was not cited by police or charged with a crime in connection with the incident. The company denied Mongeluzzi's contention that the driver had been tasked with entertaining passengers at the time.

Efforts to reach city officials, the local tour boat operator and manufacturer were unsuccessful Tuesday.

The city is being sued for what the firm of Saltz, Mongeluzzi, Barrett & Bendesky, P.C. said was an inadequate crossing signal at that intersection. They allege that a duck boat stopped at the crossing would have blocked the traffic light from Karnicki's view.

The suit seeks unspecified financial damages in the death of Karnicki, a psychologist, former college professor and advocate for seniors who was visiting the city from Beaumont, Texas.