Most of the stories in the paper start as PR writing. Of course, some stories are initiated by the news media covering breaking events -- a train wreck, for example, is covered "live" by reporters who rush to the scene as soon as their scanners pick up emergency officials' call for help. But most stories are generated as part of an information campaign by someone.
Page through today's newspaper and read between the lines. That story about an action in City Council, or on Capitol Hill -- did a reporter happen to be standing by when that new bill was introduced? Or did the lawmaker issue a statement and press release, highlighting his or her legislative initiative?
It's rarely obvious exactly who's behind the PR. A reporter will never begin a story by saying, "I got a press release today and it said..." But you can often tell how the key information -- the message of the story -- started out.
Press conferences, speeches, interviews, press releases -- these are all tools of PR writing that will sometimes be clearly identified in a news story. But even more often, the reporter will concentrate on the facts, not on the means by which they were delivered.
As you page through the paper, use your imagination. You won't necessarily know for sure, but with a little creative guessing you will usually be able to identify not only the structural elements of the story -- the 5 W's -- but also the underlying message that launched this story into the "infosphere" -- the world of information exchange.