Prichard, Ala., which stopped paying monthly checks to retired city workers when its pension fund ran out last year, is appealing a bankruptcy judge’s ruling that it did not qualify for Chapter 9 under Alabama law.

Only about 600 cities, counties, towns and special taxation districts have filed for bankruptcy (known as Chapter 9 for these sorts of entities) since 1937, said James E. Spiotto, a municipal bankruptcy expert at Chapman & Cutler, a law firm in Chicago, and fewer than 250 in the last three decades. In part, it can be hard — even impossible — to do: about half the states have statutes authorizing such filings, but some of them set limits or require elaborate approval processes. Other states have no specific provision allowing cities to pursue bankruptcy, and at least one, Georgia, bans such moves.

So far, the financial misery of the past two years has not caused a surge in bankruptcy applications; about 15 municipalities pursued bankruptcy in the last two years. But if revenue forecasts continue as predicted, 2011 might bring a rise in cities faced with such a fate.

Hamtramck (pronounced ham-TRAM-eck) did not anticipate its current circumstances. Officials in Detroit announced this year that they had for years overpaid Hamtramck in a revenue-sharing deal related to a General Motors plant that sits smack on the border of the two cities. The dispute is likely to be resolved, eventually, in court, but meanwhile, Detroit has stopped paying $2 million a year, and Hamtramck is watching a growing gap in its $18 million budget.

Here, the urgent search for services to cut has turned all attention to a realm that is also emerging at the center of budget debates in cities and states around the country: the costs of salaries, benefits and pensions of public workers.

Mr. Cooper, the city manager, says that everything else that could be cut already has been, while the city goes on spending 60 percent of its total general fund to pay for its police and firefighting forces — 75 current police officers and firefighters and about 240 former workers and spouses now on pensions. Mr. Cooper said that an entry-level police officer costs the city about $75,000 a year in salary and benefits, and yet repeated efforts to renegotiate contracts have failed.

“They kind of have the Cadillac plan,” Mr. Cooper said, “and we’d kind of like the Chevy.”

The police and firefighters question whether the city’s bankruptcy talk is really just a scare tactic for negotiation. Earlier discussions with city officials, they say, have urged them to accept pay cuts, layoffs, increased worker payments to pensions and even a suggestion that officers might pay for part of their own bulletproof vests — all this while the city has opted not to increase taxes.