A collision between Tokaido Shinkansen bullet train maintenance cars that took place on July 22 was caused by reduced braking power.

At least three out of the six crushed stone transportation cars that were involved in the crash had reduced braking power, according to Central Japan Railway.

The operator  said that necessary checks had not been carried out the day before the accident.

JR Central also said that the inspection procedure had been incorrect since its introduction in 2010.