Complex sentence: On 3rd April, 1949 the Prime Minister of India Jawaharlal Nehru laid down the foundation stone of the new building of the Institute, however, a week later, on 10th April 1949, Professor Sahni succumbed to a heart attack.
Split into simpler sentences: On 3rd April, 1949 the Prime Minister of India Jawaharlal Nehru laid down the foundation stone of the new building of the Institute. A week later, on 10th April 1949, Professor Sahni succumbed to a heart attack.