Prime Minister Narendra Modi on Friday said that the horrific Kanpur train accident in November 2016 was a conspiracy and the perpetrators carried it out sitting across the border in Nepal. Let's take a look back at what, when and how the incident took place. Here are some of the facts:

Fourteen coaches of Indore-Patna Express 19321 met with a tragedy on November 20, 2016. It derailed at Pukhrayan in Kanpur Dehat district of Uttar Pradesh, killing at least 150 people and injuring over 200 passengers. Four sleeper coaches of the train — S1, S2, S3, S4 — were badly damaged in the accident.

At around 3 am of the fateful day, the driver of the train witnessed the overhead equipment shaking and applied emergency brakes at kilometer 1290/6, according to reports.

A little later, the train jumped the tracks. The S1 and S2 coaches of the train bore the brunt of the derailment smashing into each other, trapping several people. S3 and S4 of the train also went off track.

The train had 23 coaches with 12 sleeper coaches, three general seating coaches, four AC3, one AC1 and two SLR (seating-cum-luggage) rakes.

What could have been done to avert derailment

Faulty track: Rail fracture due to contraction of the tracks in winter was identified as the likely cause of the accident, according to railways officials. Improper fittings in tracks- missing fittings and ballast on tracks lead to multiple fractures which in turn could lead to derailment.

Old, corroded railway track can also lead to derailment.  According to media sources, Commissioner of Railway Safety (eastern circle) PK Acharya, in a letter to the chief engineer, stated that almost 10-km stretch of the track was badly corroded.

ICF coaches: The train had outdated Integral Coach Factory (ICF) coaches which are infamous for piling up in case of accidents. IFC coaches have higher risk of maximum casualty.

Over loaded coaches: According to media reports, several hundred passengers were travelling in the ill-fated train. Overloading damages old tracks.

Poor safety norms: Most of the trains are not equipped with proper safety and fire equipment, lack of devices to automatically stop the train adds to the tragedy. According to media sources, the Indore-Patna Express 19321 stopped after crossing almost six overhead equipment (OHE) masts, at km number 1290/12, after the driver applied emergency brake at 1290/6.

Only in February, the National Investigation Agency (NIA) confirmed that Shamshul Huda from Dubai was the "mastermind" behind the Indore-Patna Express train tragedy in Kanpur. The Nepal Police arrested Huda after he was deported from Dubai.