Mangammal, who had gone on fast on November 28 along with several other villagers to demand arrest of those who were
behind the November 7 attack, died at Mohankumarmangalam Medical College Hospital at Salem, police said.
The woman's condition had worsened just a day after she began her fast and was admitted in a critical condition at the super speciality hospital.
Hospital sources said the woman had been suffering from viral fever for past 10 days and though "effective treatment" was given to her, she breathed her last on Monday afternoon.
The protesters, however, alleged that she died due to "inadequate treatment".
A total of 268 houses were torched, 54 vehicles destroyed, jewels and valuables looted in the violence unleashed on November 7 by caste Hindus after a man committed suicide over his daughter marrying a Dalit man of Natham Colony.
Police arrested more than 90 people after the attack came to light and National Commission for SC/ST officials and leaders of various political parties visited the colonies to condemn the violence targeting the Dalits.
Two police personnel, including an Inspector, had been suspended while the DSP of the area was shifted to Salem Range office following an inquiry pending into the alleged failure of police to prevent the attack.
Heavy police force have been posted in the area to prevent any untoward incidents, police said.