Former President APJ Abdul Kalam was on Monday admitted to a hospital in Shillong following sudden illness.

Shillong: Former President APJ Abdul Kalam, the 'missile man' who came to be known as 'People's President' died on Monday after he collapsed during a lecture at the IIM in Shillong on Monday evening.

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.

Chief Secretary PBO Warjiri told reporters outside the hospital that he had spoken to Union Home Secretary LC Goyal asking for necessary arrangements to be made for carrying Kalam's body from Guwahati to Delhi on Tuesday morning.

"The former President has been admitted to Bethany hospital in a critical condition," M Kharkrang, SP Khasi Hills said earlier.

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.

Earlier during the day, Kalam had tweeted about his function at IIM Shillong.

Going to Shillong.. to take course on Livable Planet earth at iim. With @srijanpalsingh and Sharma. — APJ Abdul Kalam (@APJAbdulKalam) July 27, 2015

President Pranab Mukherjee, Vice-President Hamid Ansari, Prime Minister Narendra Modi, Home Minister Rajnath Singh and leaders cutting across party lines condoled the demise of the former President.

"He had a special love for children and fought to constantly inspire the youth of our country," said President Pranab Mukherjee. "Dr Kalam will be long remembered for his passion, science and innovation and his contributions have enabled scientists, educationists and writers. His achievements as leader of DRDO vastly enhanced the security of our nation.

"In his passing away, we have lost a great son of India who dedicated his entire life to the welfare of his motherland. Dr Kalam was a people's president during his lifetime and will remain so," the President said.

"I got to work with him closely. I have lost an uttam marg darshak. The country has lost a son who worked for the strength of India. He had spent every moment for the youth of India. No person will be able to fill the gap left by him. His work will inspire us to work for the development of the nation," said Prime Minister Modi.

India mourns the loss of a great scientist, a wonderful President & above all an inspiring individual. RIP Dr. APJ Abdul Kalam. — Narendra Modi (@narendramodi) July 27, 2015

Dr. Kalam…my mind is filled with so many memories, so many interactions with him. Always marvelled at his intellect, learnt so much from him — Narendra Modi (@narendramodi) July 27, 2015

Dr. Kalam enjoyed being with people; people & youngsters adored him. He loved students & spent his final moments among them. — Narendra Modi (@narendramodi) July 27, 2015

Home Minister Rajnath Singh tweeted, saying that "Dr Kalam was a man of impeccable character, indomitable spirit, profound knowledge and firm conviction."

Deeply saddened at the sudden demise of the former president of India Dr. APAJ Abdul Kalam. He was an inspiration to an entire generation. — Rajnath Singh (@BJPRajnathSingh) July 27, 2015

Dr. Kalam was a man of impeccable character, indomitable spirit, profound knowledge and firm conviction. — Rajnath Singh (@BJPRajnathSingh) July 27, 2015

The death of Dr. Kalam is an irreparable loss to this nation. He has left a big void hard to fill. I deeply mourn his death. RIP Kalam Sahab — Rajnath Singh (@BJPRajnathSingh) July 27, 2015

Finance Minister Arun Jaitley said, "His contribution as a scientist and as a President was unparalleled. The whole country will mourn his death and we will all continue to remain inspired by him."

Former President Pratibha Patil also reacted and told Times Now, "He was the best human being I came across. I feel very sorry. He had good humour, had very good presence of mind and always wanted to give something to society."

Congress vice president Rahul Gandhi said Kalam "won over the hearts and minds of a nation with his warmth and wisdom."

Deeply saddened at the passing away of DrAPJ Abdul Kalam.A man of many parts-he won over the hearts&minds of a nation with his warmth&wisdom — Office of RG (@OfficeOfRG) July 27, 2015

Delhi CM Arvind Kejriwal tweeted, saying that the "nation has lost a real bharat ratna."

V sad to hear that Dr APJ Abdul Kalam is no more. Nation has lost a real bharat ratna. — Arvind Kejriwal (@ArvindKejriwal) July 27, 2015

BJP spokesperson Sambit Patra also reacted to Kalam's demise as he told India Today, "He was a man who was always surrounded by knowledge. He never had an iota of politics around him."

(With agency inputs)