Mayor Angel Taveras says he is disappointed the skyscraper will be vacant and he will do what he can to make sure it has a productive use. But he hasn't committed himself to any specific course of action.In the meantime, the Superman building will stand dark and empty. That's a mistake, says Retsinas, who lives in Providence. He likens the significance of the building in Providence to the Empire State Building in New York. "Buildings like that are also advertisements about the city. It's sending a signal to the rest of the city that we're willing to write off this building," he says. Rather than turning off the lights and letting it sit empty, Retsinas suggests a phased transition: keeping the lights on and possibly putting something in on the ground floor. In Detroit, which is hurting much more than Providence and has many more vacant large buildings, the government has worked to find tenants for some empty properties. For example, the state moved some of its offices into General Motors' old corporate headquarters after GM moved out. Rhode Island Gov. Lincoln Chafee last year suggested the state move employees into the Superman building, but that idea has gone nowhere. Washington, D.C., has gone further. It taxes vacant and blighted properties at a higher rate, giving property owners a disincentive to sit on an empty building as they wait for a turnaround in the market or try to extract something such as tax breaks. Rhode Island was once a manufacturing powerhouse and is still covered with old mill buildings, but many are vacant or have been turned into housing or office space. The state has struggled over the past 25 years or so to make the transition to a service and information economy. The most recent attempt was a $75 million state loan guarantee handed out in 2010 to a video game company started by former Red Sox pitcher Curt Schilling. The company declared bankruptcy last year, leaving taxpayers on the hook.