The New York Times is reporting Tim Russert, NBC's Washington bureau chief and moderator of Meet the Press, suffered a heart attack and died this afternoon.

Around 1pmET this afternoon, Russert was conducting a political Q&A on MSNBC.com. We're told Russert collapsed while in the tracking booth at the Washington bureau. Russert was 58 years old.

Developing...

> 3:39pm: Tom Brokaw on NBC: "It is my sad duty to report that my friend and colleague, Tim Russert, the moderator of Meet the Press, collapsed and died earlier this afternoon. He will be missed, as he was loved, greatly..."

> 3:43pm: Brian Williams, in Afghanistan, picks up coverage on MSNBC from Tom Brokaw.

> 3:48pm: Andrea Mitchell: "The preeminent journalist of our time...he carried this bureau through all the of tragedies and triumphs."

> 3:52pm: James Carville on CNN: "For me this is...he was part of my life here."

> 4:01pm: Chris Wallace on FNC: "He was a man in full. He was the king in Washington. He was the most important, influential reporter in Washington."