ThinkProgress , a source for progressive news, shut down Friday after nearly 15 years online in a shock to its staff and the man who originally launched it on WordPress.

I founded [ThinkProgress] and spen[t] a decade of my career building it from scratch and I just found out it was being shut down from this Daily Beast article, Judd Legum wrote on Twitter alongside a link to the Daily Beast, which was first to report the news.

The sites publisher, the Democratic Party think tank Center for American Progress, was unable to find a buyer for ThinkProgress, which had reportedly run a deficit for years.

Its disheartening that CAP no longer believes that independent progressive journalism is worth supporting, Legum wrote in another tweet .

CAP Action Fund Executive Director Navin Nayak said in a statement that the group was left with no choice but to close ThinkProgress as an independent enterprise focused on original reporting, citing the challenging trends in digital news media that have undermined so many iconic outlets.

Despite conversations with more than 20 potential new publishers, including several extended dialogues, those broad trends proved insurmountable in finding ThinkProgress a new home, Nayak said.

News media faces serious questions about its sustainability in the digital era. Traditionally supported by ads and subscriptions, many outlets business models have faltered as tech giants like Facebook and Google gobble up a vast majority of advertising spending. Many outlets have also struggled to balance the consumer expectation that online content be freely accessible.

Founded in 2005, ThinkProgress blossomed into an authoritative left-wing voice during the Bush administration that continued into the Obama years. Some of its earliest work to have significant impact included a report showing that a 2006 ABC miniseries about the Sept. 11 terrorist attacks was biased, with several inaccuracies . The network made changes to address the criticism, according to a report by The Guardian .

Several ThinkProgress editors have gone on to influential posts at other news organizations and in politics, including former editor Faiz Shakir, who serves as campaign manager for 2020 presidential candidate Sen. Bernie Sanders (I-Vt.).

The site will live on as a blog platform for CAP scholars, Nayak said.