(CBS) — Each step Theresa Walker takes to deliver mail carries danger.

She’s a U.S. Postal Service letter carrier feeling around for enough solid footing.

READ MORE: Illinois License Plate Fees For Some Trailers Jumped 555% Over A Year Ago, And Issue Still Has Not Been Resolved

“A couple of times I fell. Sometimes, I just sit there, get myself together and get back up,” she says.

She packs mail for more than 800 customers — snowy walks and stairs, no exceptions.

READ MORE: Chicago Weather: Warmup Ahead

Sometimes she’s forced to walk in the street because the sidewalks are buried.

“They really don’t like us to walk in the street for safety reasons,” she says. “But us letter carriers, we don’t like to bring mail back. We want to make every delivery, but we need to be able to do it safely.”

MORE NEWS: Chicago Weather: Colder And Blustery Sunday Night

If the snow is piled up anywhere around your house and you haven’t gotten your mail, chances are it’s waiting for you at your nearest post office.