PG&E Corp. on Sunday announced that CEO Geisha Williams was stepping down. Her departure comes as the utility company—California’s largest—confronts political and financial upheaval from its role in sparking California wildfires. The company said that John Simon, its general counsel, will serve as interim CEO as its board of directors searches for a permanent replacement.

Williams’s departure marks the first exit of a female CEO from the Fortune 500 this year—bringing the total down to a measly 27 or 5%. What’s more, her resignation means the U.S.’s top 500 companies by revenue has lost its first and only Latina chief executive, according to Fortune data.

Fortune’s 2017 profile of Williams digs into her unique background. As a 5-year-old in 1967, she immigrated with her family to St. Paul, Minnesota from Cuba, where her parents had been political dissidents. By age 7, she’d become her family’s main translator, conducting conversations with accountants, lawyers, and property managers. After earning an engineering degree from the University of Miami and completing a lengthy stint at Florida Power & Light, she joined PG&E in 2007. There, she worked on upgrading the utility’s electricity grid, pushed it into clean energy, and decided to decommission California’s last nuclear plant. She was named PG&E CEO in 2017.

But since then, PG&E has been dogged by liability for wildfires that have devastated its home state, with investigators tying 17 major blazes to PG&E equipment in the year Williams became chief executive. Investigators are still trying to determine if the utility’s gear was the cause of November’s Camp Fire, the deadliest in California history, but PG&E has reported an equipment malfunction in the area before the fire erupted.

In announcing Williams’s departure on Sunday, PG&E chair Richard Kelly cited the “tremendous challenges PG&E continues to face.” Indeed, hours after Williams exited the company, it said it would file for Chapter 11 bankruptcy protection amid the financial strain of the wildfire fallout. Its shares plunged on Monday.

Williams was one of the 32 female CEOs in the Fortune 500 in 2017—the highest total ever. Since then, the number has fluctuated to 24 last year, then up to 28 before Sunday’s news. The share of female CEOs in the Fortune 500 is often cited as a stark illustration of men’s lasting grip on corporate power, even as the #MeToo movement prompts a reexamination of women’s marginalization in the workplace.

But the group of female Fortune 500 CEOs is also a nod to corporate America’s utter failure to diversify its leadership ranks. As the club loses its only Latina member, it should be noted that it also has zero African-American women.