Three of Tammy Wynette's daughters filed a $50 million lawsuit blaming the singer's death on negligence by her husband and her doctor. Daughters Tina Jones, Jackie Daly and Georgette Smith said Monday that Wynette died because Dr. Wallis Marsh didn't monitor her condition closely and overprescribed medication. They also said Wynette's husband, George Richey, didn't seek medical care for her after being urged to do so by Marsh on the day of her death. The "Stand by Your Man" singer died on April 6, 1998, at her Nashville home at the age of 55. Marsh signed the death certificate, listing the cause of death as a blood clot in the lungs.