
An auditor's third report on a deadly Mexico City metro accident last year for the first time identified maintenance shortcomings as one of four causes of the collapse of the rail overpass, according to an unpublished version of the study seen by Reuters.
A Mexico City official familiar with the document confirmed the authenticity of the report by Norwegian firm DNV, which was produced at the behest of the city's government to determine the cause of the crash that killed 26 people.