Indian Railways classifies accidents from A to R in the Accident Manual:

A – Collision

B – Fire / Explosion in Train

C – Level Crossing Accident

D – Derailment

E – Other Train Accidents

Indicative Accidents

F – Averted Collision

G – Breach of Block Rules

H – Train Passing Signal at Danger (SPAD)

Equipment Failures

J – Rolling Stock Failure

K – Track (Permanent Way) Failure

L – Electrical (OHE) Failure

M – Signalling & Telecom Failure

Unusual Incidents

N – Unusual Incidents (Law & Order etc.)

P – Sabotage / Wrecking

Q – Bomb Blast / Terrorist Act

R – Other Security Related Incidents

✅ Note: Letters I and O are not used in official classification.