NEW DELHI: The accident involving the Unnao rape survivor was not a planned act but an accident caused by rash and negligent driving by the truck driver, CBI's probe into the case has found.After carrying out extensive investigation of around two months, which was monitored by the Supreme Court, CBI on Friday filed a charge sheet in the case but dropped murder and attempted murder charges against Unnao MLA Kuldeep Singh Sengar.However, Sengar, his brother Manoj and Arun Singh, son-in-law of a UP minister, have been charged with issuing threats and hatching a conspiracy against the rape survivor unrelated to the accident. He is in jail for the alleged rape of the Unnao survivor.The truck driver, Arun Kumar Pal, has been charged under IPC Sections 304A (causing death due to negligence or rash driving), 338 (causing grievous hurt by act endangering life or personal safety of others) and 279 (rash drivi-ng). The survivor's two aunts were killed in the accident.The first two sections attract a punishment of two years while the third provides for six months' jail. CBI carried out several forensic tests, including simulation test at the accident site. The incide-nt was recreated and all possible angles were probed. Call details and possible connection of the truck driver with Sengar and his associates were scanned as well. However, Sengar's role was not found in the case, said a source.Finally, Sengar was charged under Sections 120B (criminal conspiracy) and 506-2 (threat to cause death or grievous hurt). These sections attract imprisonment of up to seven years or fine or both.A speeding truck with an obscured number plate had collided near Rae Bareli with the car in which the survivor was travelling with her relatives and lawyer on July 28.While her aunts died, the survivor and her lawyer were severely injured. They were first admitted to a hospital in Lucknow and then shifted to AIIMS in Delhi on the directives of the SC. The driver was later arrested.Subsequently, the survivor's uncle, lodged in a UP jail, filed a case of murder and attempt to murder with the state police. On the family's insistence, the state transferred the probe to CBI.CBI had also booked Sengar and others on murder and attempted murder charges and formed a special probe team. SC gave CBI a probe deadline, which was extended twice. Last month, the survivor was discharged from hospital and CBI took her statement.