The Baltimore police and fire unions have one thing right in the federal lawsuit they filed this week against the city — the crisis in funding their pension is, at least in part, of city leaders' own making. Certainly a global economic meltdown hastened the collapse of the system, but dating back at least to the Schaefer administration, city officials knew that some of the benefits now on the chopping block were unsustainable, yet they never did anything about it until last year, when then-mayor Sheila Dixon attempted and then promptly withdrew reform proposals and future mayor Stephanie Rawlings-Blake convened a blue ribbon panel to study the matter. Now the city has less than a month to go before it has to either change the system or come up with an extra $65 million to fund it, on top of the $121 million deficit it's already struggling to close.

The union leaders are also right that, even in good times, the city relied on what turned out to be overly rosy estimates of the fund's likely investment returns and put less money into the system as a result. But a point the unions aren't emphasizing is that the amount of Baltimore's contributions to the fund skyrocketed in recent years. The suit alleges that from 2003-2008, the pension board ignored advice that its assumptions of investment returns should be reduced. In 2003, the city's contribution to the pension fund was $34,678,878. By 2008, it was $72,687,585. The city has already budgeted $101 million for the coming fiscal year, and if nothing is done, Baltimore will have to pay $166 million. That's a 374 percent increase in annual contributions since the first year the unions identify as the beginning of Baltimore's chronic underfunding.

The suit contends that the reform proposals being considered in the City Council are illegal and must be stopped, and that the city should make up for the previous underpayments — which it calculates at more than $230 million — with interest. The question is, how do the unions expect the city to come up with all that money? Should the city lay off police and firefighters in order to save their pensions?

It's not the police and firefighters' fault that the city made promises to them it couldn't keep. But acknowledging that fact doesn't make the money to pay for their benefits magically appear. The council is working on a revised version of a pension reform bill, and Mayor Rawlings-Blake is expected to introduce new proposals as early as Monday. Union officials have offered some concessions, though not enough, and they say they're still willing to negotiate. But the clock is running out, all sides they need to be realistic about what the city can afford, now and in the future.