Investigators focus on whether an inexperienced23- year old driver and excessive speed were to blame for a commuter train derailing in western Japan.

• 日本西部发生了一次通勤列车脱轨事件。现在调查人员正在集中研究该次事故的原因是否在于23岁的列车司机经验不足，以及列车超速驾驶。