The President Mrs. Pratibha Devisingh Patil and the Prime Minister Dr. Manmohan Singh have condoled the death of Dr. H.N.Sethna. In a condolence message Mrs. Patil said, Dr. Sethna played a crucial role in the successful conduct of India's first peaceful nuclear test in 1974. She said that in his passing away the country has lost a well-known nuclear scientist and a true patriot.In his message, Dr. Manmohan Singh recalled his long and fruitful personal association with Dr. Homi Sethna and described him as a pillar of India's nuclear energy programme.