Faulty signalling due to two botched repair operations led to the train accident in Odisha’s Balasore that claimed at least 293 lives, an investigation by the Commissioner of Railway Safety has found out, reported the Hindustan Times.

The first repair work was carried out in 2018, while the second was done just hours before the accident took place.

On June 2, one of India’s deadliest rail crashes occurred in Balasore when two coaches of the Yesvantpur-Howrah Express derailed near the Bahanaga Road railway station. The derailed coaches came in the path of the speeding Coromandel Express on the adjoining track and collided with it. A goods train was also hit in the process. More than 900 people were injured.

In his report submitted to the Railway Board last week, Commissioner of Railway Safety AM Chowdhary said that wires inside a location box were wrongly labelled and the error remained undetected for years, ultimately leading to a mix-up during the repair work, according to The Indian Express.

The probe found that a wiring diagram – meant to guide technicians on how the wiring is to be reconnected after maintenance work – was changed on paper and duly approved as early as 2015, but was not corrected physically.

“It is also learnt… that there was a similar incident of mismatch [of signals] between the intended route set by signals, and actual route taken by train, on May 15 at Bankranayabaz Station in Kharagpur Division of South Eastern Railway, on account of wrong wiring and cable fault,” the report said, according to the Hindustan Times.

The report said that if corrective measures had been taken after this incident, the accident on June 2 would not have taken place.

Chowdhary also said that the station master, who controls the signals for train operation, failed to detect “abnormal behaviour” of the signalling control system that could have prevented the tragedy, reported The Indian Express.

The report also said that the Railways’ initial response to such incidents should be faster. “Railway Board should review the system of disaster-response in the Zonal Railways, and also the coordination between the Zonal Railways and various Disaster-Response Forces [NDRF and SDRF],” the report said, according to the Hindustan Times.

Also read: Why a ‘fail-safe’ signalling system fails to prevent deadly train crashes