BISMARCK, N.D. (AP) _ State officials say they have discovered a data breach on one of their servers that stores information from the state’s Workforce Safety and Insurance agency, but say they believe no personal information was stolen.

Mike Ressler with the state Information Technology Department tells the Bismarck Tribune that unusual activity was detected on server on May 29. The compromised server was secured and data was locked down.

The agency says it’s been determined that personal information, like Social Security numbers, was stored on the server. Officials say there’s no evidence someone moved any of the data off the server or duplicated any of the personal information.

The data at risk is about 43,000 incident reports and 13,000 payroll reports that were filed online between 2006 and 2013.