When the Los Angeles Police Department goes on tactical alert, it's not unusual, but it's an event. This is the nation's second largest city, and the LAPD is the proverbial thin-blue line. Reporters who are used to listening to LAPD frequencies alert whenever there's a "tac alert."

It means all-hands have to be on-deck -- nobody's going home early -- because something serious is going down. It also means that lower priority calls -- say, for example, a business dispute -- are not responded to at all.

But when it happened this week, nothing serious was going down. Except maybe the city budget:

On Tuesday the LAPD called a tactical alert for its Central (which includes downtown, the Eastside and parts of northeast L.A.) and South (which includes South L.A., San Pedro, Wilmington and Harbor Gateway) bureaus.

The reason, reports Celeste Fremon at Witness L.A: "radio call load."

That's not a riot or a SWAT action, folks. That means the LAPD was on heightened alert because it simply did not have enough badges on the streets to deal with its normal calls. And this was on a Tuesday (not New Year's Eve, not the day of a Lakers championship).

A source close to the department says indeed the LAPD didn't have enough officers working that day and the reason is budget cuts that have limited officers' overtime and forced them to take vacation and other time off.

The union representing Los Angeles police has claimed that while City Council leaders have proclaimed that they have spared the department from actual layoffs as a result of L.A.'s budget crisis, cuts in civilian staffing have meant that officers are doing desk work instead of street duty.

A source told us it was not a labor action to demonstrate the dire straights of the department's budget.

In fact, only non-union "command staff" can call a "tac alert."