General Motors Co. CEO Mary Barra will apologize to the families of the 13 people the Detroit automaker says were killed in crashes linked to faulty ignition switches in since-recalled cars, and vowed that the automaker will “do the right thing,” David Shepardson and Melissa Burden report in the Detroit News.

Barra will testify Tuesday before a House Energy and Commerce panel and face questions about why the automaker knew about problems with the switches for more than a decade before finally recalling them in February and March. Also testifying is National Highway Traffic Safety Acting Administrator David Friedman.

“We will not shirk from our responsibilities now and in the future. Today’s GM will do the right thing,” Barra will say, according a copy of her written testimony released by the committee Monday. Barra will offer her “sincere apologies to everyone who has been affected by this recall — especially to the families and friends of those who lost their lives or were injured. I am deeply sorry.”

“Sitting here today, I cannot tell you why it took years for a safety defect to be announced in that program, but I can tell you that we will find out. When we have answers, we will be fully transparent with you, with our regulators, and with our customers,” Barra will say, adding the company has taken steps to immediately improve how it address safety problems. “These measures are only the first in making things right and rebuilding trust with our customers. As I’ve reminded our employees, getting the cars repaired is only the first step. Giving customers the best support possible throughout this process is how we will be judged.”