A teenage girl died when she was struck by a train in Yarnbrook on Wednesday.
The incident happened at the Aintree Avenue crossing at around 8.20pm and it is believed the teenager lived in the area.
Emergency services were quickly at the scene. Police do not believe the incident to be suspicious. British Transport Police is leading the investigation into how it happened.
A BTP spokesman said: “Inquiries are ongoing to establish the full circumstances leading up to the incident and to confirm the identity of the person.”
Officers have been carrying out door-to-door inquiries near where the collision happened. Earlier in the evening, Wiltshire Police were called to a report of a missing person in the area and it is thought the two incidents may be connected.
A BTP spokesperson said: “We are aware of that report to Wiltshire Police but we have yet to identify the victim so we can’t confirm the two are definitely linked at this stage.”
Following the collision, rail services between Trowbridge and Westbury were suspended until around midnight with a temporary bus service running for commuters.
Passengers on the train involved in the collision had to stay on board while police carried out initial enquiries.
A First Great Western spokesperson said: “Our driver was very shaken and was looked after very quickly. We appreciate everyone’s patience while the emergency services responded and did what they could.”
Any witnesses can call BTP on 0800 40 50 40, quoting incident 520 of January 15, 2014.