that's why we've taken extraordinary steps. >> reporter: do you think, looking back, someone at gm should have, when they saw this happen and an internal investigation, reached out to candice anderson? >> again, poppy as you look across this, making the right changes we need to make with the learnings from the lucas report and making sure we're the industry leaders in safety moving forward and we've taken steps to do the right thing. >> reporter: gm is fixing its defective cars and have apologized to victims and their families. >> i am deeply sorry. >> reporter: when you come back to the crash site vindicated knowing this wasn't your fault, what do you think? >> the guilt is definitely lifted. but what happened in the tragedy, of course, it's still there. the pain is still real. >> reporter: and nothing will bring michael back. for the past ten years, michael's mother, rhonda, couldn't bring herself to lay a headstone for her son.