PHILADELPHIA — Amid all the sobering discussions of what happens when cities run out of money, fiscal sleight of hand and time, the most telling detail at a conference on distressed municipalities here last week just might have been the one about the fire truck that was the wrong color.

Robert Stout, the former finance director of Vallejo, Calif., was talking about the spiraling public safety costs that ultimately led his city to declare bankruptcy when he mentioned the time a fire broke out two blocks from his home there, not long after the city had closed some of its firehouses to save money.

“The first fire truck that went by was yellow,” Mr. Stout recalled. “Our fire trucks are red. So the first fire truck to respond was on mutual aid from a town 20 miles away. That gives you some sense of what you are facing when you get into these situations.”

These situations, as he put it delicately, are still rare, but not as rare as they once were. A number of cities and counties around the country with long-term problems have found themselves pushed over the edge by the recession and its lingering aftermath. The audience here listened to war stories from the emergency fiscal managers that Michigan has installed in a couple of its most distressed cities. Even Nassau County, on Long Island, one of the wealthiest counties in the nation, has seen its perennially troubled finances placed under a state-appointed control board.