The three persons, all fish-sellers, were crossing the tracks after buying fish from the wholesale market situated beside the Champahati station when a Sealdah-bound EMU local train mowed them down at around 6.30 am, South 24-Parganas district police officials said.
Two of those who died were siblings and identified as Pintu Mondal (30) and Mamoni Mondal (25), the police said.
Another woman, aged around 65 years, died while being taken to a hospital. She is yet to be identified.