Personal and financial data of nearly 2,000 Riverside city employees were sent out across City Hall's e-mail system because of a computer operator's error, officials confirmed this week.
The message, intended for payroll department databases, reached the inboxes of about 2,300 city employees late last week, said Assistant City Manager Tom DeSantis.
City officials did not learn of the mistake until the following morning, when they shut down the city's internal e-mail system, blocking access to inboxes for about 12 hours while they deleted the messages, DeSantis said.
The correspondence contained workers' Social Security numbers and financial deduction information for 401(k) and other accounts, as well as "specific identification information," DeSantis said, without elaboration.
About 20 copies of the confidential e-mail were opened, DeSantis said, although there was "no indication" that any personal data had been misused.
Preliminary investigations by local law enforcement suggested that the transmission was accidental; Riverside police and the Riverside County district attorney's office were continuing their inquiries, DeSantis said.
The computer operator who sent the e-mail was put on administrative leave during the investigation. That employee did not follow newly established city procedures to encrypt sensitive material, DeSantis said.
City Hall converted to a new e-mail system last week, officials said.
"Trust is paramount," DeSantis said, adding that steps had been taken to ensure that employees were protected.
The Riverside employees union, which just wrapped up negotiations with city officials, complained that security safeguards should have been in place.
"It was just an accident waiting to happen," said Greg Hagans, a senior office specialist with the city parks department and president of the Riverside chapter of Service Employees International Union, Local 1997, which represents about 850 municipal employees.
City officials notified workers of the situation with several faxes and mailed a letter to employees' homes Thursday. The city also offered $50,000 in identity-theft insurance to anyone whose information was in the e-mail.