Toni Randolph, an award-winning journalist at Minnesota Public Radio (MPR) who championed diverse voices in news stories and newsrooms and mentored the next generation of young reporters, died Sunday. She was 53.

Randolph joined MPR as a reporter in 2003 and covered everything from the St. Paul Winter Carnival to homelessness and immigration issues. She was named news editor for new audiences in June 2010; at that time, it was a new position aimed at connecting with ethnically diverse Minnesotans.

In a memo to colleagues Sunday, MPR's executive director for news and programming, Nancy Cassutt, said Randolph died "while undergoing surgery for cancer treatment."

The memo continued, "Because Toni was such a private person, many of us did not even know she was sick but she had been fighting cancer for more than three years. [Her brother] Morgan told me … that she came to work in pain and many of us just didn't know."

Randolph, a native of Buffalo, N.Y., was a news director at her local public radio station and covered state politics at a Boston station before joining MPR. She earned a master's degree at the Columbia School of Journalism and went on fellowships to China and Liberia.

She was a prolific reporter, with 22 stories listed on MPR's web page in 2010 alone. In 2013, she wrote a personal essay about Macy's closing its store in downtown St. Paul. Earlier this year, she wrote an obituary on a Somali youth activist.

She was passionate about training high school and college journalists, particularly those of color. She worked as a mentor for the University of St. Thomas' ThreeSixty Journalism program and was a journalism camp full mentor for the first time in 2013.

A student journalist interviewed Randolph that year, asking what made her want to work with teens.

"Teens are excited about the work they do," she said. "They show up, they want to work and they do the story or project — whatever it is they're working on. And when teens are excited about the work they do, that helps me get even more excited about the work I'm doing."

Randolph was honored with the Widening the Circle Award from ThreeSixty Journalism in 2014. She dedicated the award to her mother.

"I don't feel like I am widening the circle," she said. "I feel like I'm completing one."

In 2015, her Young Reporters Series won a Gracie Award from the Alliance for Women in Media.

She also was active in the national and local chapters of the National Association of Black Journalists.

"Just as Toni inspired countless young people, she has been one of the strongest voices for diversifying newsrooms — including our own," Cassutt wrote in her memo. "May we all follow Toni's example and build on her amazing legacy."

Jon McTaggart, CEO of American Public Media, said in another memo Sunday that Randolph was "a gifted and dedicated journalist."

"Toni has been an important part of the fabric of Minnesota Public Radio," he wrote. "She made countless, meaningful contributions to our public service. She believed in our mission, and she believed in her colleagues and friends. She will be greatly missed, every day."

Funeral arrangements are pending.