BOISE, Idaho — Families of residents at an Idaho treatment center for people with developmental delays and mental illness say in a planned lawsuit that some of those living at the facility have been abused and neglected.

News outlets reported Thursday that the families filed notice of a forthcoming lawsuit against the Southwest Idaho Treatment Center in Nampa. They plan to seek class-action status, reports said.

"Instead of providing needed support and care intended to allow their return the community, their family and friends, and their homes, they were beaten, neglected, and abused. Some residents died from the abuse and neglect, and then SWITC staff tried to cover it up," the legal notice said.

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The families said they are seeking negotiations with state officials, who could not immediately be reached for comment.

The notice follows two years of legal action regarding staff conduct at the state-run center 20 miles west of Boise.

DisAbility Rights Idaho says it found 49 cases of abuse and neglect during a yearlong investigation. At least 14 residents were victims, the advocacy group said.

"In a facility with only about 23 residents, these are appalling numbers. In our opinion, these point to systemic failures," said Jim Baugh, former executive director of DisAbility Rights Idaho.

Last year the state agreed to pay $10,000 to settle a lawsuit by the mother of Moses Rodriguez, a 24-year-old patient who died after living at the center.