A delay while applying the brakes led to the derailment of the Secunderabad-bound Golconda Express near Warangal in Andhra Pradesh.
An engine and two bogies of the 7201 Golconda Express derailed and fell from a rail overbridge, resulting in the death of 18 persons on July 2.
"As per provisional findings, the derailment had occurred due to a delay in application of brakes," Commissioner of Railway Safety R P Agarwal, who conducted an inquiry into the accident, said in a release in Hyderabad on Thursday night.
The findings have been forwarded to the Central government, he added.
