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At least nine people were killed and 100 injured. Two carriages were so badly twisted that they were sealed shut. The automatic system designed to prevent trains from being on the same track had apparently been shut off while work was done. Clearly it is too early to draw any conclusions from this incident until more facts are known, but it is quite possible that, if the system worked reliably, the train controllers may have lost familiarity with the manual procedures. Alternatively, perhaps news of the service withdrawal was not adequately disseminated.