Three coaches of a Borivli-bound slow local train decoupled at Marine Lines station on Sunday. This is the first such safety lapse in Western Railway. There were no injuries or damage as the train was moving at a very low speed. An inquiry has been launched by the railway authorities. Couplers, which connect the coaches of a train, are designed to absorb the stress of acceleration, deceleration, and braking. The cause of the decoupling is being investigated, and it could have been due to a fault with the material or maintenance.