“Glee” star Naya Rivera drowned in Lake Piru in Ventura County lake this past summer because a boat she rented with her son from the county did not have a ladder and other safety equipment, according to a wrongful death lawsuit filed Tuesday.

Rivera rose to stardom playing the lesbian cheerleader Santana Lopez on “Glee” during its entire run, from 2009 to 2015.

This past July, she and her four-year-old son rented a pontoon boat at Lake Piru and went for an afternoon swim.

She disappeared, and her son was found alone on the boat hours after he and his mother were last seen. According to the complaint, the current and wind on the lake carried the pontoon away from where they went into the water and the two were separated.

Rivera’s son, Josey Dorsey, was able to make it back on the boat and heard his mother crying for help but he couldn’t find anything to throw to her as she struggled for her life, the complaint filed in Ventura County Superior Court says.

“Josey then looked back at the water for his mother, and saw that Naya disappeared,” the lawsuit filed by Dorsey and Rivera’s estate says. “Josey yelled for help and cried alone in the boat until he was found more than an hour later” by a county employee.

A search and recovery crew found Rivera’s body five days later after an extensive search of the lake. The coroner ruled the “Glee” star’s death an accidental drowning.

According to the lawsuit, which also includes claims of negligent infliction of emotional distress, Rivera’s drowning was preventable.

The pontoon she rented from the county Parks and Recreation Management lacked a “safely accessible ladder, adequate rope, an anchor, a radio or any security mechanisms to prevent swimmers from being separated from their boats,” according to the lawsuit.

“Disturbingly, later inspection revealed that the boat was not even equipped with any flotation or lifesaving devices, in direct violation of California law, which requires that all pontoons longer than 16 feet be equipped with flotation devices,” the plaintiffs say in their complaint.

They also say the signage on the boat was outdated and inaccurately claimed the boat complied with U.S. Coast Guard safety standards.

The lawsuit also details the deadly history of Lake Piru, with 26 known drownings since the 1950s. They plaintiffs say there are no signs at the docks, the shore or any of the popular swimming areas about “the strong currents, low visibility, high winds, changing water depths, underwater caves, ledges, and dropoffs, or the trees, brush, and other debris that congest its waters due to vastly changing water levels and winds.”

Rivera’s body was found in 25 to 30 feet of water, in a part of the lake with an underwater shelf nearby that is 65-70 feet deep and thick with heavy debris and trees that rise up from the lakebed, according to the complaint.

In addition to the dangerous conditions, the plaintiffs say the rental process was inadequate and the life vest was optional. They also say the “Glee” star was a strong swimmer.

The complaint disputes news accounts that Rivera boosted her son back onto the boat and says she likely had no idea he made it back to the boat safely.

Amjad Khan from Brown Neri Smith Khan represents the plaintiffs.

An email to Ventura County’s county executive officer and county counsel was not immediately answered by press time.

— By Nathan Solis, CNS