By Steven Greenhouse
The United States Postal Service has long lived on the financial edge, but it has never been as close to the precipice as it is today: the agency is so low on cash that it will not be able to make a $5.5 billion payment due this month and may have to shut down entirely this winter unless Congress takes emergency action to stabilize its finances.
“Our situation is extremely serious,” the postmaster general, Patrick R. Donahoe, said in an interview. “If Congress doesn’t act, we will default.”