Sweltering residents and elected officials want to know why it's taken so long to restore power following storms that cut electricity to millions last week.
But the answer is complicated.
Above-ground power lines are vulnerable to lashing winds like the ones that swept from the Midwest to the mid-Atlantic last Friday. But moving power lines underground can incur huge costs that get passed on to consumers. And severe weather strains an already aging power infrastructure.
The storms have killed 24 in seven states and the District of Columbia. About 1.26 million customers remained without power Tuesday.
The response to the storms has renewed the debate about moving the lines underground. D.C. Mayor Vincent Gray urged the change. A Pepco official said Tuesday that it'd be a multi-billion-dollar project.