This is a summary. To read the whole story subscribe to BostonGlobe.com
It was nearly five years ago that any doubts were laid to rest among engineers at General Motors about a dangerous and faulty ignition switch. At a meeting on May 15, 2009, they learned that data in the black boxes of Chevrolet Cobalts confirmed a potentially fatal defect existed in hundreds of thousands of cars.
But in the months and years that followed, as an expanding trove of internal documents and studies mounted, GM told the families of accident victims and other customers that it did not have enough evidence of any defect in their cars, interviews, letters, and legal documents show. Last month, GM recalled 1.6 million Cobalts and other small cars, saying that if the switch was bumped or weighed down it could shut off the engine’s power and disable air bags.