Crunch time at US Postal Service: Five questions about post office closings.

The US Postal Service may shutter as many as 3,700 post offices nationwide, to help close a $20 billion revenue shortfall between now and 2015. How'd the venerable USPS get into this position? Here's the answer to that question and four others concerning what's next for the Postal Service.

2. What may be lost in terms of post offices, jobs, and services?

Some 3,653 of the USPS's 31,871 post offices, about 12 percent, are under review in every state except Delaware, as well as in the District of Columbia.

Many post offices and branches under review are in rural areas and provide little revenue. In fact, 84 percent of the locations on the list take in less than $27,500 in annual revenue and have less than two hours of work a day, according to Dean Granholm, the Postal Service's delivery and operations vice president.

Savings from the closings could be as much as $200 million. But it also means potentially massive layoffs: As many as 3,000 postmasters, 500 supervisors, and 500 to 1,000 clerks could be let go, according to Mr. Granholm.

The first closings are expected by January 2012.

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