The names, Social Security numbers and home addresses of nearly 1,740 former school employees in Chicago were mailed by mistake, prompting concerns the information could be used for identity theft.
All Printing & Graphics Inc., which Chicago Public Schools hired to print and mail a packet of health-insurance information to the former employees, said Sunday that it hadn't realized one document it sent contained the personal data.
The Broadview-based printer mailed a spreadsheet used to make mailing labels, thinking it was a list of health-care providers, district spokesman Michael Vaughn said.
It is not certain how many of the former employees received the 125-page list of personal information, Vaughn said.
"We sincerely apologize for the error in the mailing," he said.
The general manager of All Printing & Graphics, Ralph Fowlkes, cited "human error" and also apologized.
Chicago Teachers Union officials said they were shocked about the mix-up.
"We are outraged and extremely disappointed that the Board of Education did not take greater precaution in protecting the privacy of these individuals," the union said in a statement.
One retired elementary teacher said she spent weeks shredding old receipts and other papers to try to protect herself from identity theft - only to receive the list with the personal data in the mail on Saturday.
"I worked at it to keep my identity closed and hidden, and in a moment it was gone. Seventeen hundred-plus people now have it," said 60-year-old Peggy Janik. "We feel totally violated. It's horrifying."