PITTSBURGH  This can be a quirky city. It has no discernable street grid in many of its 89 neighborhoods. The trademark cuisine is sandwiches with French fries as an ingredient. And the natives speak with a distinct accent and vocabulary, known as Pittsburghese, that is neither Midwest nor East Coast.

The quirkiness can mask some insecurity. Residents are all too aware that the city continues to shrink  down to about 310,000 people this year from its peak in 1950, which makes it just the 60th largest city in the country, according to the Census Bureau  and that it still has the same budgetary problems that led it to be placed under state financial control in 2003.

So it is not surprising that many residents are still piqued by the laughter from White House reporters last month when President Obama’s press secretary, Robert Gibbs, announced that the leaders of 20 of the world’s biggest industrial and emerging economies  the Group of 20  would hold a meeting here in September.

“If the people in Washington were snickering, it’s because they don’t understand Pittsburgh and probably haven’t been here,” said Paul Hennigan, a lifelong resident and the president of Point Park University, one of the many colleges that have helped revitalize the city. “If you don’t know Pittsburgh, you would snicker about an old Rust Belt industrial city down on its luck, not the beautiful, cutting-edge place it is.”