Congress president Rahul Gandhi on Friday hailed late environment activist GD Agarwal for his contribution towards saving the holy river Ganga and vowed to take his fight forward.

Agarwal passed away at the age of 86 at a hospital in Uttarakhand’s Rishikesh on Thursday, 111 days after he began a fast for a pollution-free Ganga.

The Congress leader described Agarwal as “the true son of mother Ganga” adding that he gave away his life to save the river.

“It is rivers like the Ganga that have made India. Saving the Ganga is like saving the country. We will never forget him and will take his fight forward,” Gandhi wrote on micro-blogging site Twitter in Hindi.

Agarwal had begun his hunger strike on June 22 demanding government measures to save the Ganga. He  died of a heart attack at the All India Institute of Medical Sciences in Rishikesh.

The 86-year old former IIT-Kanpur professor had demanded that steps be taken to make the river free-flowing for natural cleansing, and also a ban on construction of all hydroelectric projects along the tributaries of the Ganga besides enactment of the Ganga Protection Management Act.

Agarwal had sent several letters to Prime Minister Narendra Modi, who had in 2014 pledged on the banks of the Ganga in Varanasi that immediate steps would be taken to ensure cleaning of the holy river.

Agarwal had given up water a couple of days ago after government failed to respond to his satyagraha. On October 9, he was moved to the AIIMS in Rishikesh.