The 1st vehicle to derail was the 2nd, a diesel power car (it was a hybrid) & being heavier than other vehicles & with a higher centre of gravity. Looks like the next one to derail was the other diesel power car, the penultimate vehicle towards the rear of the train.
It could be that there are serious implications for other high speed railways where the signalling systems are not all that they maybe should be! There also seem to be serious questions to be asked about drivers being distracted by telephone calls!