New Delhi: Prime Minister Narendra Modi pays tribute to former president APJ Abdul Kalam at Palam technical area of IGI Airport in New Delhi, on July 28, 2015.The former president died on Monday in a private hospital in Shillong after he collapsed while delivering a lecture on “Liveable Planet” to students of the Indian Institute of Managment-Shillong. (Photo: Amlan Paliwal/IANS)