Applicability of Section 304 & 304 A ?

This is a Rly.Electrical works contract . Work completed in all respects on 3/8/2016 and charged with 25 kv electricity. As per rule no person is allowed to work without proper Rly authority on that area. If any work to be done contractor should give a letter to rlys regarding work and to arrange power blocks to work. As we have no work beyond 3/8/2016, instructed all workers not to do any work on 25 Kv Electricity. Now the point is the person died due to electrical accident on 10/8/2016 and nobody was present at work place and also work location does not belong to us. Contractor has given a list of authorised workers to Rly. authorities and the person is not in that list. Now based on information taken from others police say that this death is due to negligence and informed that police himself lodged FIR under sec.304 & 304A on contractor. Where no execution of work exists , no Rly. person & contractor present at that death location how the section 304 IPC applicable.