Director Lynn Shelton, 54, died Friday in Los Angeles as the result of a previously unidentified blood disorder, according to her agent, Adam Kersh.

Shelton, who directed hit shows such as “Little Fires Everywhere” and “Glow,” collapsed after a week of feeling ill, her collaborator and romantic partner, Marc Maron, told Deadline in a statement Sunday.

“It’s devastating. I am leveled, heartbroken and in complete shock and don’t really know how to move forward in this moment,” Maron said.

Shelton, who was born in Ohio in 1965, spent much of childhood in Seattle. She studied at Oberlin College in Ohio and the University of Washington School of Drama before moving to New York for a master’s in fine arts, Kersh said.

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Shelton made her first film, “We Go Way Back,” in 2006 after having seen French director Claire Denis speak at Seattle’s Northwest Film Forum. Her third film, “Humpday,” premiered in 2009 at the Cannes Film Festival, where it won the Grand Jury prize.

Shelton also had a successful career in television, directing episodes for hit shows such as “New Girl,” “Fresh Off The Boat” and “The Mindy Project.” Her most recent work, a miniseries based on the novel “Little Fires Everywhere” by Celeste Ng, premiered in March.

“Little Fires Everywhere” producer and actress Reese Witherspoon mourned Shelton’s death Saturday on Instagram, calling Shelton a “vibrant, talented, and soulful filmmaker.”

“Lynn also shared so much of her life with us,” Witherspoon wrote. “Her love of her son, how motherhood changed her life, her life changing decisions that made her the woman she was. I feel so fortunate that I got to collaborate with Lynn on both The Morning Show and Little Fires Everywhere.”

Other celebrities, such as Ava DuVernay, Kerry Washington and Judd Apatow, grieved Shelton’s death on social media, telling stories about her on set and their experiences with her.

Comedian Mindy Kaling wrote a tribute on social media, posting a photo of her and the director from the set of “The Mindy Project.”

“Her lovely, sunny energy was infectious and actors always drifted to video village between takes to be around her,” Kaling wrote. “She had such a quiet power and I will miss her.”

Shelton is survived by her son, Milo Seal.