Urgent safety advice has been issued following the derailment of a diesel-carrying freight train which led to a major fire in Llangennech near Llanelli.
A major incident was declared in the village after the wagons came off the tracks and burst into flames at around 11.30pm on Wednesday, August 26.
Thick smoke and large flames could be seen for miles around and police officers set about evacuating 300 people from their homes.
A major operation also swung into action to prevent the 330,000 litres of spilled diesel infiltrating and damaging some of the internationally important wetland areas surrounding the accident site.
One week after the incident, workers used heavy duty cranes to lift the wagons away, which were around 25 to 30 tonnes each.
Since the incident, the Rail Accident Investigation Branch (RAIB) has been looking into the derailment.
Today it said firms responsible for maintaining wagons which usually carried dangerous goods should review their processes to manage the risk of brake failure.
This should include assessing the competence of employees and the security of fastenings, said the RAIB.
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A preliminary RAIB report published in September found that some of the train's wheels were damaged by a fault with the brakes after a component became loose.
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Investigators said there was "no record of any check on the tightness of the fastenings ever having been made".
The train, owned by DB Cargo UK, was travelling from Robeston oil refinery in Milford Haven, Pembrokeshire, to a fuel distribution terminal in Theale, Berkshire.
It was travelling at around 30mph when the derailment happened. No-one was hurt in the derailment or subsequent fire.
