One thing that must be acknowledged is that in their understandable distress, bereaved parents are an unreliable source of information. At one collapsed school in Dujiangyan we were told by a father that the building was ten years old, and that pupils were supposed to have been moved out two years ago, while a mother told us that the school had been built in 1993, and that the authorities had known there were problems with the construction since 1999.

The Dong Qi school is reported to have been built in the 1960s. This would seem to be supported by the pictures hanging in the entrance, which clearly date from a time of Sino-Soviet cooperation, though the building itself does not look nearly as old as that.

But this is a trivial matter in the context of the loss the parents have suffered, and they deserve, and must be given, a full investigation into their tragedy, and a full and public account of its findings.

My heart quails at the thought that such devastation could have been wrought by deliberate acts of dishonesty. I am repelled by the idea that any person could have inflicted this torment for the sake of what would have been trivial amounts of money, however unintended or unforeseeable the consequences. But there is a clear case to answer.

The evidence for the prosecution stands in mute accusation, to the north-west of the fallen school and only a few feet away. The Girls' Dormitory is a drab building, with none of the carefully-wrought decoration that graced the school. It is an ugly cement-rendered affair, six storeys high, and it stands almost unscathed.

The lintel above every window has flexed and cracked, and the render has fallen away. Apart from that, nothing. If only the earthquake had happened in the night, hundreds of girls would have been in this dormitory and would have escaped any injury.

Feet from the collapsed school, the dormitory stands unscathed.

In terms of the structure of the two buildings, it is impossible to see how the framing of the main school building compared with the dormitory, because the dormitory is undamaged. The only visible difference is in the brickwork. The dormitory was built of small, solid, compact housebricks, while the main school walls were of much bigger and lighter airbricks. The Staff Accommodation blocks, which also collapsed, appear to have been built of these airbricks, while other nearby blocks of apartments, built of the smaller housebricks, did not.

Is it possible that this alone could explain the catastrophic collapse of the school building, while the dormitory stood undamaged?