Petra Mayer, who famously served as NPR Culture's books editor, had died. She was only 46.

NPR confirmed that the beloved editor passed away suddenly on Saturday at the Holy Cross Hospital in Maryland. NPR's senior vice president for news, Nancy Barnes, confirmed the saddening update in an email to staff.

"Petra was NPR through and through," Barnes wrote. "To say that Petra will be missed simply seems inadequate."

Petra Mayer's cause of death was not clearly confirmed, but doctors believe she died due to pulmonary embolism.

The Cedars Sinai's official website describes the illness as a phase wherein a blood clot occurs in a blood vessel in a person's body - most often, in the legs. The clot then travels to a lung artery, which blocks the blood flow and causes the blockage.

It remains unknown whether she suffered from another disease before suffering from pulmonary embolism.

Colleagues, Friends Remember Petra Mayer

Following Mayer's death, her friends and colleagues immediately paid tribute to her and remembered her works.

NPR released an official statement through USA Today, calling the editor's death a heartbreaking loss for the whole company.

"Petra's passion for her work, her love for her colleagues, and her joy sharing books with public radio listeners have made a lasting impact. We extend our deepest sympathy to her family & friends," NPR said.

NPR culture critic Glen Weldon, also shared a message on Twitter, saying, "She was the best and rarest species of nerd, whose enthusiasm was eager and sincere and open and inviting. She wanted you to love the stuff she loved, and supplied you hard incontrovertible evidence to support her thesis. Jesus, she was the best of us."

"We just spoke a few weeks ago about spooky reads and one of her recs is now a nightly favorite. My sincerest condolences to us all," NPR's "Here and Now" co-host, Tonya Mosley, wrote.

Before her death, Mayer famously joined NPR as an engineering assistant in 1994. After attending Amherst College, she started working as a news writer for WBUR in Boston while finishing her master's degree in journalism at Columbia University.

She officially returned to NPR in 2000. In 2012, Mayer joined the NPR Books team.