Very sad, but an entirely foreseeable accident.
Did the train not have any communication cord or equivalent ? Presumably not, since prompt use of such would have stopped the train and allowed most of the victims to escape to the trackside.
A survivor who's TV interview I saw last evening on ITN said that the emergency chain had been pulled
An horrific event. The suggestion of the ITN report was that gas canisters used to fuel food cooking by passengers on-board had been "sneaked" onto the train, and that scanners to deter this practice are not present at all stations in Pakistan.