Mary Barra, General Motors CEO and longtime member of Fortune’s Most Powerful Women community, joins Fortune CEO Alan Murray and senior editor Ellen McGirt on this week’s episode of Leadership Next.

The GM chief made the news for her strongly worded letter to employees mourning the racist killings of George Floyd, Breonna Taylor, and Ahmaud Arbery, among others. In it, she wrote: “Let’s stop asking ‘why’ and start asking ‘what.’ What are we going to do? In this moment, we each must decide what we can do—individually and collectively—to drive change…meaningful, deliberate change.”

She tells Murray and McGirt that she is an action-oriented engineer, and that as she reflected on these wrongful deaths, she was inspired to ask how her company could drive real change while many other CEOs simply release unactionable statements of solidarity. From that idea sprang the Inclusion Advisory Board, which she said should be completely assembled by the end of June, with the aim of making GM “the most inclusive company in the world.” She also said that she is focused on driving that supportive inclusivity not only within GM, but in the communities in which GM operates, within its supply base and in the business world at large through her membership with the Business Roundtable. That organization, a collection of CEOs that advocates for business-friendly policies, has a plan focusing on health care, access to capital, criminal justice, and education (the committee on which Barra sits) to address inequality.

Around the 12-minute mark, Geoff Colvin, a longtime business journalist and Fortune writer who has reported on Mary Barra closely for years, joins McGirt to talk about Barra’s leadership. He explains how she has transformed the stubborn company culture through behavior, how she revolutionized training, and how she used starting her tenure as CEO during a disastrous and fatal ignition-switch scandal as an opportunity to drive action for good.

Colvin said that the hardest assignments in business are those that ask leaders to change company culture, and altering the deep-seated culture at GM was likely one of the hardest. But Barra did it. And for that reason he believes that Barra will be successful in her diversity and inclusion efforts.

To effect change, especially as the global workforce returns to work after the coronavirus lockdowns, Barra said fostering trust is key.

“I think trust is at the center of everything,” she said. “A lot of it starts with communication. It’s hard for someone to trust you when they don’t know what you’re doing or why you’re doing it.”