Mr. Chi'en, acting human, lost his cool. After finishing his report, he turned to his harassers and yelled something on the order of, "What is your problem, man?" That last sentence is sanitized here. The reporter's outburst included a well-worn expletive, one of the seven dirty words deemed no-nos by the Federal Communications Commission. You hear it on New York streets only, oh, three dozen times a day.

That was Mr. Chi'en's foolish thing. He thought he was off the air, he says. But he knew right away that he had gone too far. When he went back live moments later, he apologized, but to no avail. Before the morning was out, WCBS had fired him.

No question, he behaved poorly, Mr. Chi'en said the other day. "I'm a professional, and I know I'm not supposed to use those words," he said. "I thought the station had switched to tape. But I'm not making any excuses. I should have known better."

Still, under the circumstances, was his sin so great that he deserved a career beheading? Mr. Chi'en, 36, does not believe so. "I definitely deserved disciplinary action," he said. "I wasn't expecting to be fired."

Some of his colleagues were dismayed. So were people whom he covered for Channel 2 and, before that, for NY1 News. Mr. Chi'en, a respected reporter, specialized in transportation news. Letters of protest have been sent to WCBS by representatives of the Metropolitan Transportation Authority, the Transport Workers Union and the Straphangers Campaign. Most days, you can't get those groups to agree on a lunch order.