(NBC NEWS) - The pointed questions and concerns about how and why General Motors allegedly hid defects with faulty ignition switches, which may have led to at least 13 deaths and dozens of injuries, turned personal this morning on Capitol Hill.
"How do you tell a little boy that his dad could have been here for a 57 cent part that GM chose not to install in our son's car?" Leanne Stork, mother of Donnie Stork who died in a 2010 crash, said.
For the fourth time in this on-going investigation, lawmakers grilled top executives about what they've labeled a cover-up. They wanted to know why it took more than a decade to recall 2.6 million vehicles.
"Indifference, incompetence, and deceit among engineers," Missouri Senator Claire McCaskill said.
Documents show GM engineers and executives knew in 2001 that ignition switches could rotate out of the run position, shutting off the engine. This would also disable the power steering, brake assist and disable the airbags.
For the first time today, Rodney O'Neal, the CEO of Delphi, the contractor that made the switches, testified.
O'Neal said his company just learned about the problem early this year.
"Our product met the requirement of the customer," O'Neal said.
"So, no responsibility ?" Nevada Senator Dean Heller asked.
O'Neal replied no.
"Management was the problem here, not the workers," Senator McCaskill said.
The strain was visible on GM CEO Mary Barra's face as lawmakers aggressively questioned her.
The panel was pushing for the automaker's chief lawyer to be fired and for more victims to be included in the company's victim compensation program.
"We will compensate the innocent victims of this tragedy," Ken Feinberg, Administrator of the GM compensation fund, said.
Families will begin filing claims August first.