we saw some tough questions on day one. how did mary barra do today? >> reporter: she faced even tougher questions from the senate committee in two-plus hours of testimony. the ceo of general motors opening her testimony saying she is deeply sorry for the lives lost. we know that at least 13 lives were lost as a result of this ignition switch failure. but democratic senator claire mccaskill, who chairs this committee, in the hearing said let's call this, quote, a culture of cover-up, quote, egregious violations of public trust, to give you a sense of the tone in the hearing room. senators just like members of the house wanting to know why general motors did not come forward for a decade about a problem that they knew about that in 2004 if not earlier. what we do know is gm created a new part, a new ignition switch part that didn't give that part another number. that is very abnorm for this company or any auto company to do.