1) you had placed safety barriers to barricade the construction site .
2)road user must have been driving rashly and hence broke the safety barriers and fell into deep pit and died
3) police must have recorded your statements .
4) has FIR been lodged under section 304 (a)
5) section 304 ( a) deals with causing death by negligence and is punishable with imprisonment upto 2 years or fin e
6) it has to be proved that death arose on account of your negligence . if safety barricades are in place and you had taken precautions necessary while carrying on construction work it would be difficult to prove negligence under section 304 a) of IPC