Mary Barra, the chief executive officer of General Motors, returns to Capitol Hill Wednesday. This time, a Senate subcommittee will ask her about the faulty ignition switches linked to 13 deaths.
On Tuesday, Barra said General Motors is still investigating, but new emails have emerged about who knew what and when, CBS News' Jeff Glor reports.
An email obtained by CBS News shows multiple GM executives, including Lori Queen - the vehicle line executive in charge of the Chevy Cobalt - knew an ignition switch could have been fixed nine years ago.
A separate email in 2005, from Delphi, a GM parts manufacturer, said the Chevy "Cobalt is blowing up in their face in regards to turning the car off."
GM decided not to make fixes.
Rep. Diana DeGette, D-Colo., said during Barra's testimony Tuesday, "They were warned again and again over the next decade, but they did nothing."
Barra, who started at GM in 1980 and became CEO in January, testified before Congress Tuesday.
DeGette showed a faulty ignition switch and said it would have cost 57 cents to fix.
Committee Chairman Tim Murphy, R-Pa., said, "When GM concluded ... that the tooling cost and price pieces are too high, what does that mean?"
"I find that statement to be very disturbing," Barra said. "If that was the reason this decision was made, that is unacceptable."
Barra blamed the "old" GM for a culture centered around cost and lack of communication. She frequently apologized to families whose loved ones had been killed or injured in crashes.
Barra was questioned why the faulty ignition switch was redesigned in 2006 without changing the part number. Mechanics had no way of distinguishing the new parts from the old, defective batch.
Barra said, "It is inconceivable, it is not our process, and it is not acceptable."
But the committee often expressed frustration Barra wasn't able to provide more. Rep. Joe Barton, R-Texas, said, "What you just answered is gobbledygook."
Murphy wondered how much Barra prepared. He asked, "Did you review the documents that GM submitted to the committee?"
Barra said, "No I did not. There was over 200,000."
The Senate will also hear Wednesday from David Friedman, the acting head of the National Highway Traffic Safety Administration. He said Wednesday that GM didn't give them enough information to order a recall. GM did indicate Tuesday they may pay families who lost loved ones before 2009. Under the terms of the bankruptcy agreement in 2009, GM was immune from those claims.