CHICAGO (CBS) — Despite the unofficial pledge to deliver mail in snow, rain, heat and gloom of night, the U.S. Postal Service is being hammered today by power outages.

As WBBM Newsradio 780’s Julie Mann reports, several post offices in the north and northwest suburbs were left without power Wednesday, as a result of the damaging storms. The outages limited retail services at those locations.

LISTEN: Newsradio 780’s Julie Mann reports

The Postal Service says portable generators have been brought into Post Offices in Des Plaines, Glencoe, Lake Bluff, Lake Forest, Mount Prospect, Park Ridge, Rolling Meadows and Wheeling, allowing sorting and delivery in the 600 ZIP codes. But both may be limited Wednesday.

“Despite the severe storms, employees have reported for duty,” acting Lakeland Post Office District Manager Charley Miller said in a news release. “We will make every effort to provide the best service to our customers at the retail counter as well as delivery in their neighborhoods.”

A Post Office spokesman said the facilities plan to be fully operational Thursday.