Bre Payton, a conservative writer at The Federalist and frequent guest on television news outlets including Fox News Channel, died Friday after a sudden illness, according to her employer. She was 26.

Those who knew and worked with Payton at the Federalist website expressed shock Friday over her death. She had been on television just days earlier.

“Bre has passed,” publisher Ben Domenech tweeted. “We are devastated. Last we saw her, she was her funny, smart, vivacious self. Now lost to us so suddenly.”

A few hours earlier Friday, Domenech asked for prayers and linked to a CaringBridge website that said Payton was found unresponsive on Thursday in San Diego. Doctors, according to the post, determined she had contracted the “H1N1 flu and possibly meningitis.”

Payton, who was based in Washington, was in California this week guest-hosting a show on the One America News Network. On Wednesday, Payton told her Twitter followers to tune in that night to see her on television.

But the next morning, according to the CaringBridge post, a friend found her “unresponsive and barely breathing.”

“She immediately called 911 and Bre was taken to the hospital where she was admitted to the ICU, sedated & intubated, and doctors began working up a diagnosis,” the post said. “After a CT scan and hours of testing, they have determined she has the H1N1 flu and possibly meningitis.”

The Federalist, in a post on the site Friday, remembered Payton as someone who “brightened the lives of everyone around her.”

“She was joyful, hard-working, and compassionate, and she leaves behind friends and colleagues for whom she brought nothing but sweetness and light,” the post said.

In recent weeks, Payton appeared as a guest on Fox News’ "Your World with Neil Cavuto" and "Trish Regan Primetime" on Fox Business. She has also been on "Fox & Friends" and "Fox News @ Night."

“I cannot believe this. @Bre_payton was such a beautiful light, smart and funny and kind and talented,” Fox News anchor Shannon Bream tweeted. “Please pray for her broken hearted loved ones, who are undoubtedly reeling. She was far too young.”

According to her biography at The Federalist, Payton wrote stories on “subjects ranging from Kanye West to Supreme Court rulings, to 2016 and breaking news.” She previously worked as a reporter for Watchdog.org and received her degree in political journalism from Patrick Henry College.