WHEN the NBC News host Tim Russert died on June 13, NBC tried to hold back the news from going public for more than an hour to notify his family vacationing in Italy and presumably to prepare for what became six hours of coverage on its cable news outlet, MSNBC.

And King Canute, ancient legend has it, tried to hold back the tide.

Mr. Russert collapsed from a heart attack in NBC’s Washington newsroom around 1:40 p.m.; he was treated there and then taken to a hospital, arriving at 2:23 and being pronounced dead shortly thereafter, according to press accounts. The network, in the voice of its respected former anchor, Tom Brokaw, announced the news at 3:39.

Long before Mr. Russert’s death was reported on air, however, it was flashing across the Internet via the text-messaging service Twitter and the online encyclopedia Wikipedia.

Television networks have a tradition of allowing a network suffering a death to make the announcement first. Other news outlets, including The New York Times and The New York Post, were about five minutes earlier in reporting Mr. Russert’s death for their Web sites.