31-year-old runner Amandeep Singh Jagade succumbed after collapsing mid-race during the 21km courseCHIKKABALLAPUR: A 31-year-old runner died after collapsing during Monsoon Marathon at Nandi Hills Sunday morning. He is suspected to have suffered a cardiac arrest.Amandeep Singh Jagade, a Punjab native, was living in Bengaluru and working for a private company at Manyata Tech Park.The marathon, organised at Nandi Hills, featured 10km and 21km categories and drew more than 4,500 participants. Police have registered a case of unnatural death and are investigating.The marathon began around 6.30am. He was taken to a medical camp at Nandi Hills, where he was given preliminary treatment. CPR was performed near the entrance to the hills before he was rushed to hospital.