Nabam Runghi, credited to be the man behind making Itanagar the capital of Arunachal Pradesh, died following a prolonged illness, family sources said Monday.
He was 84 and is survived by four wives and several children.
He passed away at his residence in Yupia on Sunday and his last rites would be performed on Tuesday, they said.
In his condolence message, Khandu wrote, "It pains my heart to write to you at this moment of extreme grief. I humbly endure to share with you the saddest times of your life though I know that it would be hard to do so and ease the pain you and your family are going through."
"The news of sad demise of Runghi has come as shock to me. He was conferred Gold Medal in the year 2017 by Government of Arunachal Pradesh for his outstanding contribution to the state and the society. He will be remembered as a first generation leader, a pioneer and an architect of Itanagar and a great social worker. His demise is a great loss to the state," Khandu said in the letter.
May Almighty God bless the departed soul with eternal peace in heavenly abode and give strength to you and your family to bear the irreparable loss, the chief minister added.