And another one: Thai train derailment No injuries.

Fourth derailment since July 13  Bangkok Post

Possible cause heat expansion of the track.
That clickety-clack sound of the train is the sound of the wheels passing a slight break in the track to allow for heat expansion.

The frequency of recent rail mishaps could become a detriment to Thai tourism 

wikipedia State Railway of Thailand 

• The older passenger cars in service were manufactured in the 1960's.

• The newest passenger cars date from 1996.

Nong Kai 2005

Bangkok Airport exit 1966