Kalam, who would have turned 84 in October, was confirmed dead more than two hours after he was wheeled into the ICU of Bethany hospital in a critical condition following the collapse at around 6.30 pm.

According to reports, Kalam suffered a massive cardiac arrest during the lecture at IIM, Shillong.

Considered the most popular President, Kalam became the 11th head of the state and occupied the post between 2002 and 2007 but lack of consensus denied a second term in office for a man who came from outside political spectrum.

Meghalaya Governor V Shanmughanathan, who rushed to the hospital on hearing the news of his admission, said Kalam died at 7.45 pm. Despite medical team best efforts, he could not be revived.

Doctors from the army hospital and North Eastern Indira Gandhi Regional Institute of Health and Medical Sciences (NEIGRIHMS) rushed to Bethany hospital but their efforts proved to be of no avail.

A seven-day national mourning will be declared by the Centre, Union Home Secretary LC Goyal said. Both the Houses of Parliament are likely to make obituary references and adjourn as a mark of respect to his memory.

Avul Pakir Jainulabdeen Abdul Kalam rose from humble origins to become the President in the most unexpected manner during the NDA government under Atal Bihari Vajpayee after an all party consensus minus the left parties that saw him through in an election which he won handsomely.

An aeronautics engineer from Madras Institute of Technology, Kalam was considered the brain of missile programme in India got and as Chief Scientific Adviser to Vajpayee was also instrumental in the Pokhran nuclear test in 1998.

As President, Kalam utilised any opportunity that came to him to address students, especially school children, to dream big so that they became achievers in life. A bachelor, the former President was a veena player and was deeply interested in Carnatic music. He was vegetarian all his life.