All three victims were working on behalf of a Gurgaon-based company which supplies and maintains high masts.
The JSCA in a release said the workers were working at high mast tower number 3 with trolleys and ropes in the stadium when they met with the accident and suffered critical injuries.
The injured were immediately rushed to Rajendra Institute of Medical Sciences, but all three succumbed to their injuries, the release said.
During installation of the main rider unit and accessories, including a power lift with cage for maintenance of mast and luminaries, suddenly the rope carrying the cage snapped off and the cage in which the workers were working, fell down, causing grievous injuries to them, as per the release.