ANN ARBOR, Mich. (Michigan News Source) – The University of Michigan said a computer hack caused the school to temporarily cut off the internet in August and the data breach impacted 230,000 people.

The university detected suspicious activity on its computer network on Aug. 23 so the campus network disconnected from the internet.

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Third-party experts helped the university investigate the incident and found that the breach impacted certain systems from Augusts 23 through August 27. The hack exposed the personal information of certain students, applicants, employees, alumni and donors. The compromised data includes social security numbers, driver’s licenses, financial information and health information.

University of Michigan officials say they are worked to strengthen its systems.

Letters have been mailed to those affected. A call center can be reached at (888) 998-7088 from 9 a.m. to 9 p.m. EDT Monday through Friday.