A woman whose nine family members died when a duck boat sank in Missouri on July 19 is alleging in a new lawsuit that the operators knew that the design of canopies on the vehicles could create a “death trap” for passengers.

The lawsuit, filed on Tuesday in federal court in Missouri, joins at least six others brought by survivors and family members of the victims of the sinking, in which 17 of the 31 people on board drowned. The Missouri Attorney General’s Office also brought a suit last week. Like many of the lawsuits, the case alleged negligence and strict products liability claims, asserting that Ripley Entertainment Inc. and previous tour operators were aware since 1999 that the design of the duck boats were unsafe.