The incident took place near Sansarpur Dhala between Khagaria and Mansi railway stations at about 08.30 am as Saharsa-Patna 12567 Rajya Rani Express hit a motorcycle with three occupants while it was trying to cross the track, Anil Kumar, Khagaria GRP police station incharge said.
While one Rituraj Bhagat (28), who was driving the bike, was killed on the spot, his wife Komal and sister Riya who were riding pillion sustained grievous injuries in the incident, he said.
The bikers hailed from Sansarpur village, Kumar added.