As news spread of PBS NewsHour co-founder Jim Lehrer’s death Thursday, those who knew him best and admired his work mourned on social media. Lehrer died at 85 on Jan. 23 at his home in Washington.

The most prominent voices included journalist Dan Rather, who referred to his late friend on Twitter as a gentleman and “a helluva journalist” and said that “in the trenches of electronic journalism over the decades, I met a lot of people. Few approached their work with more equanimity and integrity.” House Speaker Nancy Pelosi (D-Calif.) echoed the sentiment, tweeting: “Our nation has lost a champion for truth and transparency. As one of the founders of PBS NewsHour, as well as its longtime host, Jim Lehrer worked to keep America’s leaders accountable to the people. My prayers are with his wife, Kate [Staples], and their family."

Judy Woodruff, who spent more than a decade working with Lehrer on what is now called the PBS NewsHour, tweeted that she was “devastated to share news that my dear friend” died and that she was “sending love to his Kate and their family.”

CNN’s Brian Stelter, who anchors the network’s weekly “Reliable Sources,” reflected on Lehrer’s recent appearance on his show: “He seemed well. He wanted to share his concern about America’s divisions — he said ‘division is the story now.' ” He included a link to the interview.

Others, such as CNN correspondent Josh Campbell, a former FBI supervisory special, shared memories of Lehrer. Campbell said he had “the pleasure of once flying with Mr. Lehrer. After we settled into our seats, he leaned over and quietly said, ‘I’m guessing Air Marshal, and just want to say thank you.’ ‘Close!’ I exclaimed. ‘How’d you know?’ 'My business is studying people,' he said. A legend, indeed.”

Robert Costa, a Washington Post reporter who also hosts “Washington Week” on PBS, tweeted: “What a life. What a journalist. A sad day but his legacy and example will carry on. I will miss him, particularly the love of country and politics he brought to everything he did.”

Many shared similar thoughts. Katie Couric called Lehrer “a legendary journalist and anchor.” Stephen Fee, communications director for PEN America, referred to him as a “giant in broadcasting. A mentor and leader to thousands.” Fox News’s Bret Baier heaped praise on Lehrer, calling him “a very genuine, gracious man in person” and adding that he was “one of the best debate moderators & an inspiration to a whole generation of political journalists — including this one.”

PBS NewsHour correspondent Lisa Desjardins wrote, “This man changed news so much for the better. So grateful to be part of Jim Lehrer’s legacy. Very sad he is no longer in the world. But, suspect Jim Lehrer would just tell us to move on and cover the story.” She added: “As my mom just texted me, he was such an example of decency and professionalism. That’s the mission he gave us at NewsHour.”

Several people shared what has been dubbed Lehrer’s rules of journalism, which include “Do nothing I cannot defend,” “Assume there is at least one other side or version to every story,” “Assume the same about all people on whom I report,” and “Carefully separate opinion and analysis from straight news stories and clearly label everything.”