Ex-Chief Secretary of Haryana and former World Bank executive director Dhanendra Kumar Garg died after a fire broke out at his residence in the Hauz Khas area here, the police said on Thursday.His son was injured in the incident and is undergoing treatment.According to officials, a call regarding the fire was received at the Hauz Khas police station at 11.18 pm on Wednesday.Police teams and fire personnel rushed to the spot and two fire tenders were deployed to douse the blaze.Eighty-year-old Garg, a 1967-batch IAS officer of the Haryana cadre, and his son were shifted to a hospital. Garg died while undergoing treatment at the AIIMS trauma centre.The police said five persons, including family members and domestic help, were present in the house at the time of the incident.Preliminary investigation suggested that the fire might have been triggered by a blast in an indoor air-conditioner unit.Statements of eyewitnesses have been recorded and the police have ruled out foul play. Officials added that further action would be taken after getting technical reports.Garg, who hailed from Gangoh in Uttar Pradesh, served as the Chief Secretary of Haryana, Chairman of the Competition Commission of India, Chairman of the National Highways Authority of India, Telecom Secretary, GST Chairman and Excise Commissioner. Following his retirement from service, he also served as executive director at the World Bank.