U.S. Postal Service employee Craig Conner tries to navigate a mail cart to his vehicle Thursday morning Feb. 21, 2013 in downtown St. Joseph, Mo., shortly after the snow storm started.

 

              U.S. Postal Service employee Craig Conner tries to navigate a mail cart to his vehicle Thursday morning Feb. 21, 2013 in downtown St. Joseph, Mo., shortly after the snow storm started.
U.S. Postal Service employee Craig Conner tries to navigate a mail cart to his vehicle Thursday morning Feb. 21, 2013 in downtown St. Joseph, Mo., shortly after the snow storm started. Winter storm warnings were issued from eastern Colorado through Illinois Thursday. (AP Photo/St. Joseph News-Press, Todd Weddle)