線路内点検から判明
https://twitter.com/v5nPNydbvSU0xaY/status/805719686981689346


https://twitter.com/smallwhite777/status/805719921829085184




https://twitter.com/AkomoT_7130/status/805721056879067136


https://twitter.com/vvasrta/status/805724509017780224