"Every day he brought Washington home to his viewers, and made all of us better. My thoughts and prayers are with his family -- especially Maureen, Luke and his father Russ," Stephanopoulos said.
"He loved the game of politics and he was an unbelievably fierce competitor," Stephanopoulos said.
Around Washington and across the country, regular viewers of Russert's show expressed the same shock, sadness and admiration as those in journalism and politics.
"It was really a stunning loss. I was shocked. it was the last thing I expected to hear when my friend told me. Everybody knew Tim Russert. How can you not know Tim Russert?" said Elizabeth Searle, a Episcopal priest in New York.