MUNISING (AP) — A mentally ill Michigan prison inmate died of dehydration while being restrained in a chair, according to a lawsuit.

Jonathan Lancaster’s death last March at Alger Correctional Facility was the result of days of neglect by prison medical staff, the lawsuit alleges.

“What makes this case so tragic is that it could have been so easily avoided,” said Kevin Ernst, an attorney representing Lancaster’s estate.

The state Corrections Department, noting the litigation in federal court, declined to comment Thursday.

Lancaster, 38, was in prison for robbery and gun crimes in Wayne County.

The lawsuit states that he was transferred to an “observation room” at the prison last March after showing bizarre behavior and being found in his cell with feces on the floor. He refused meals and appeared gaunt and pale.

A few days later, according to the lawsuit, the prison made plans to transfer Lancaster for medical treatment. The lawsuit says he died after being left alone and restrained in a chair.