A New York Times investigation found serious flaws in the basic construction of Mexico City's metro that appear to have led directly to its collapse in May, in which 26 riders were killed after a train plummeted 40 feet toward the traffic below We took thousands of photographs of the crash site and shared them with several leading engineers who reached the same conclusion about what went wrong. Read more: https://nyti.ms/35k7Gp0 | The New York Times