A Linn woman has pleaded not guilty in the death of her 2-month-old son after the boy drowned in a bathtub. Twenty-eight-year-old Rachel Sweet waived her right to a preliminary hearing and was bound over for trial on charges of endangering the welfare of a child and involuntary manslaughter. Cooper Bentley Sweet, was left alone in the bath according to prosecutors. That led to his death in March. An autopsy determined the boy drowned.