The official explanation: Nothing like this has ever happened before and two, no one wants to take any chances. The memory of the Khanna disaster is still fresh.

``All because of a single goods train,'' says N D Gandhi, Divisional Engineer, Panipat-Ambala section. ``We have never seen anything like this.'' On December 3, a goods train bound for Ludhiana was stopped at Ambala after an inspector detected a ``flat engine tyre'' which had scraped off the rails.

Officials admit that it was ``plain luck'' and ``increased vigilance'' that led to the fractures being detected. ``If the Khanna tragedy hadn't happened, maybe we would have missed it.'' How could the goods train get on track with a flat tyre? If it happened en route, why was no action taken by the driver? Is there any system of monitoring in place? These are larger questions and as of now not on the priority list, officials admit. For, first train serviceshave to be restored.

Until today, repair work till Kurukshetra is over. Every kilometer, teams are at work, drilling holes and fixing fishplates at places marked with a red cross on the tracks.

``As soon as the cracks were detected, ultrasonic scanners were brought in and the entire stretch till Ambala inspected. More than 100 fractures in the rail and 1,400 in the rail joints were detected and marked with a red cross. The rail fractures can be simply welded but for the joints, first the cracks have to be welded, then fishplates drilled on both sides of the crack and then rewelded. Each fracture takes about two hours to repair,'' explains Gandhi.

With ultrasonic scanning having been completed, it is fishplating which is in progress now. Gandhi adds that three trains -- two goods and one passenger -- were allowed to pass at the speed of 30 km per hour on the section. Having tested the track, the speed will be exceeded to 60 km per hour.