AIIMS doctors said the BJP stalwart and former external affairs minister died of a cardiac arrest.
Illustrious Bharatiya Janata Party leader and former External Affairs Minister Sushma Swaraj, who brought a rare empathy and a human approach to India's diplomacy, passed away on Tuesday night suffering a massive cardiac arrest.
She was 67.
Swaraj was taken to the All India Institute of Medical Sciences around 9:30 pm in a critical condition and was straight away taken to the emergency ward where a team of doctors attended to her but could not revive the astute politician, AIIMS sources said.
"She suffered a massive cardiac arrest. She was brought to AIIMS around 9:30 pm but doctors could not revive her," a source said.
Her body will be kept for three hours at the BJP headquarters on Wednesday for party workers and leaders to pay tributes, BJP working president J P Nadda said.
Her last rites will be performed at the Lodhi crematorium, he said.
Nadda told reporters the body will be kept at the party headquarters from 12-3 pm for people to pay respects on Wednesday after which it will be taken to Lodhi Crematorium for the last rites.
One of the most prolific politicians of India, Swaraj's sudden demise triggered a wave of shock and grief with leaders cutting across political spectrum paying glowing tributes to the astute leader.
"A glorious chapter in Indian politics comes to an end. India grieves the demise of a remarkable leader who devoted her life to public service and bettering lives of the poor. Sushma Swaraj Ji was one of her kind, who was a source of inspiration for crores of people," Prime Minister Narendra Modi tweeted.
Just hours earlier, Swaraj tweeted to congratulate Prime Minister Narendra Modi after the Centre's move to revoke special status for Jammu and Kashmir and bifurcate the border state into two Union Territories secured Parliament's approval.
"Narendra Modi ji - Thank you Prime Minister. Thank you very much. I was waiting to see this day in my lifetime," she had said.
Defence Minister Rajnath Singh, Finance Minister Nirmala Sitharaman, Law Minister Ravi Shankar Prasad, Health Minister Harsh Vardhan, Environment Minster Prakash Javadekar, HRD Minister Ramesh Pokhriyal and Union Minister Smriti Irani were among the top leaders who visited the hospital.
"Her loss is irreparable and the void left by her can never be filled. It's a huge loss to the party and the nation," Nadda said.
Prasad said it was a personal loss for him. "We used to address her as 'didi' and the respect she commanded was phenomenal. She was fine in the morning and then suddenly we got this news. It is a painful loss for me and for the nation," he told reporters.
Senior BJP leader Shahnawaz Hussain also grieved the loss, saying Swaraj had guided him in his career and "she was a leader liked by everyone, from the ruling to the opposition parties".
As external affairs minister, Swaraj brought a sense of assertiveness in India's diplomacy and played a key role in resolving the Doklam standoff with China in 2017.
She had also played a key role in India approaching the International Court of Justice challenging a Pakistani military court's death sentence to Kulbhushan Jadhav.
Swaraj was known for prompt response on Twitter to address grievances of overseas Indians She had also played a key role in strengthening BJP across the country in 1990s.
The former Union minister had a kidney transplant in 2016 and had opted out of contesting Lok Sabha polls earlier this year for health reasons. She is survived by her husband Swaraj Kaushal and daughter Bansuri.
"Extremely shocked to hear of the passing of Smt Sushma Swaraj. The country has lost a much loved leader who epitomised dignity, courage & integrity in public life. Ever willing to help others, she will always be remembered for her service to the people of India," President Ram Nath Kovind tweeted.
In 1996, during the 13-day government of Atal Bihari Vajpayee, Swaraj was instrumental in taking a key decision in ensuring live telecasting of Lok Sabha debates as the union cabinet minister for Information and Broadcasting.
Swaraj was external affairs minister from 2014 to 2019, leader of the Opposition in the Lok Sabha from 2009 to 2014, minister for information and broadcasting in Vajpayee government from 2000-2003. She was also chief minister of Delhi in 1998.