A signal fault led to the Odisha train disaster, coupled with a change that occurred during ‘electronic interlocking’, Indian railway minister suggested on Sunday. Electronic interlocking is a system designed to stop trains colliding by arranging their movement on the tracks. “We have identified the cause of the accident and the people responsible for it,” India’s Railway Minister Ashwini Vaishnaw said, but added it was “not appropriate” to give details before a final investigation report. There was confusion about the exact sequence of events though reports cited railway officials saying a signaling error had sent the Coromandal Express running south from Kolkata to Chennai onto a side track. It slammed into a freight train and the wreckage derailed an express running north from India’s tech hub Bengaluru to Kolkata that was also passing the site. Mounds of debris were piled high at the site of Friday night’s crash near Balasore in the eastern state of Odisha, as workers started to clear the smashed carriages and the blood-stained wreckage where hundreds were also injured. Hospitals have been overwhelmed by the number of casualties. Pradeep Jena, Chief Secretary of Odisha State, confirmed that about 900 injured are currently hospitalised. A high school close to the crash site is turned into a makeshift morgue.