DETROIT (WWJ) – Roughly 18,500 patients at Henry Ford Health System have possibly had their personal information stolen in a data breach.

Officials say the breach was discovered in early October after the email credentials of a group of employees were stolen, which gave the thief access to patients’ records.

READ MORE: Election Denial Probe Looms Over Critical Races In Michigan

Personal information viewed or stolen may have included a patient’s name, date of birth, medical record number, provider’s name, date of service, department’s name, location, medical condition and health insurer. Neither Social Security numbers nor credit card information were revealed.

READ MORE: Police Search For Suspect In Fatal Shooting On Detroit's West Side

“We are very sorry this happened,” Henry Ford Health System said in a statement. “We take very seriously any misuse of patient information, and we are continuing our own internal investigation to determine how this happened and to ensure no other patients are impacted.”

MORE NEWS: Amy Black, Who Was Sentenced To Life In Prison At 16, Granted Parole

Patients who feel their information was compromised can request new medical record numbers to protect themselves. Patients who received a notification letter are asked to call 844-327-2396.