Social activist and academic Ilina Sen, known for her work in Chhattisgarh, died of cancer on Sunday, The Indian Express reported. She was 69 years old.

“She passed away around 7 pm,” Association for Democratic Rights office-bearer Ranjit Sur told the newspaper. “Binayak da [her husband Binayak Sen] and others are there. It is a great loss.”

Sen spent many years in Chhattisgarh to work with trade unions, the underprivileged and the Adivasi community. She also wrote two books Inside Chhattisgarh: A Political Memoir and Sukhavasin: The Migrant Woman of Chhattisgarh. The activist taught at Mahatma Gandhi International Hindi University in Maharashtra.

Her husband Binayak Sen, a doctor and human rights activist, was in 2010 convicted and sentenced to life imprisonment by a trial court in Chhattisgarh on charges of conspiring to commit sedition and for allegedly assisting Maoists. In 2011, the Supreme Court granted bail to him and said that no case of sedition was made out against the rights activist.

Also read: After being jailed: the nightmare for Binayak Sen’s family