Years ago, on one of the first nights I appeared on live television to do a news commentary, a studio cameraman, trying to ease my visible nervousness, told me, “Relax, there’s only half a million people watching this show.”

He wasn’t exaggerating. This was the heyday of WJZ-TV’s “Eyewitness News,” with Jerry Turner and Al Sanders, when the station was drawing 25-point ratings. Each point is worth roughly 10,000 households, and the ratings experts figure two adults are watching in each household. Do the math, if you must.

For local TV news, that was another lifetime ago.

You can see it in local ratings that have dropped over the past decade for every station and, for WJZ, plunged dramatically since the controversial firing of 5 o’clock anchor Mary Bubala last month.

As The Sun’s TV critic David Zurawik reported this week, WJZ lost almost half of its remaining 5 o’clock audience – those highly-valued viewers between 25 and 54 – since Bubala’s departure.

The station that once drew half a million viewers is now drawing roughly 20,000 people among those who are most highly prized by advertisers – and not much more among other viewers.

That little clicking sound you hear is the sound of people turning the channel – or turning off their sets altogether.

It was the firing of Bubala that arguably set off the latest ratings drop, but it’s also part of a pattern. Beginning about two decades ago, cable TV started stealing away viewers. But we’ve seen a steady run of electronic innovations since then that have cut even more heavily into viewer numbers.

People who once turned on the 11 o’clock news for the latest weather reports are now staring at their phone all day long for any updates. Who needs the 11 o’clock program to tell us it’ll be warm tomorrow?

But the firing of Bubala put WJZ in an awkward position beyond technology. She asked a question about race in an awkward, insensitive way that offended a lot of people – but her firing was seen as an insensitive act of overkill, even by many who didn’t like her original question.

In WJZ’s heyday, when Turner and Sanders made the station one of the highest-rated in the entire nation, its strength was not only the appeal of its anchors, but the consistency of its supporting cast.

They had a stable full of people who were familiar faces here for years and years. Those days have vanished. And in the next few weeks, two of WJZ’s veteran on-air faces will be retiring as well. (Stay tuned on that bit of information.)

Those days and nights of half a million viewers are long gone, and aren’t coming back.

A former Baltimore Sun columnist and WJZ-TV commentator, Michael Olesker is the author of six books, including “Tonight at 6: A Daily Show Masquerading as Local TV News” (Apprentice House). His most recent, “Front Stoops in the Fifties: Baltimore Legends Come of Age,” was reissued in paperback by the Johns Hopkins University Press.