Missing bolts among issues that sparked Mexico City metro collapse, auditor finds

FILE PHOTO: A train car is seen at the site where an overpass for a metro partially collapsed with train cars on it at Olivos station in Mexico City, Mexico May 4, 2021. REUTERS/Henry Romero/File Photo

MEXICO CITY (Reuters) - A deadly Mexico City metro collapse in May was caused in part by missing bolts in beams in an overpass that already had deficiencies before a major earthquake, according to an independent auditor's report released on Tuesday by the city government.

The analysis by Norwegian company DNV was the latest installment of its technical opinion on the May 3 collapse - Mexico's biggest train accident in years - that killed 26 people when an overpass and train carriage suddenly plummeted onto a stream of cars near the Olivos station in the southeast of the city.