FRIDAY'S tragedy at Potter's Bar brought to our railway network the unenviable record of six fatal accidents in six years. Our front page headline on Saturday was entitled to ask: "How many more?"

Yesterday's interim report from the Health and Safety Executive points to poor maintenance as the likely cause of the latest disaster.

It is safe to conclude therefore that the tragedy at Potters Bar - just like the tragedy at Paddington and the tragedy at Hatfield - was avoidable. Four nuts on a set of points were not in position. And because of a shoddy piece of maintenance, seven people have lost their lives.

While it may be tempting to lay the blame at the individual or individuals responsible for failing to rectify the fatal fault on the line on the approach to Potters Bar station, culpability goes far wider.

It is clear that ineptitude is endemic in Railtrack's approach to track maintenance.

That is why we supported Stephen Byers' decision last October to place Railtrack in administration and we welcomed his promise to create a new structure. But eight months down the line, the industry remains in a state of limbo.

Railtrack remains responsible for the upkeep and maintenance of the network. But, in administration, it is no longer accountable.

If there is one lesson to be learned from the disaster at Potters Bar it has to be that the procrastination must come to an end. Whatever the cost of compensation to shareholders, Railtrack has to be wound up and replaced by a body whose sole remit is safety and maintenance.

Never again must we allow responsibility for rail safety to be placed in the hands of people charged with the task also of providing the best possible returns to investors.

And it is imperative that a new Secretary of State is appointed to introduce these much-needed reforms.

In the eight months since putting Railtrack into administration, Mr Byers has shown little indication of an ability to perform the duties expected of him.

We doubt the suitability of a minister who struggles to keep tabs on a handful of close advisers to concentrate on the arduous and complicated task of restoring the public's faith in the railways