The assistant driver, who appeared in his mid 30s, was killed after the wedding chariot built on the TATA Van, BR 30 B 0783, suddenly collapsed.
However, the identity of the deceased is yet to be ascertained, said DSP Lokendra Shrestha.
The incident occurred while the wedding procession was arriving at Nathuni Das's house from Manpaur of Bihar State of India.
The body has been taken to Zonal Hospital, Janakpur for postmortem.
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