WESTFIELD, Mass. (WWLP) – Westfield residents who were transported by the fire department’s ambulance may have been affected by a possible data breach.

Those patients may have received a letter from Comstar Ambulance Billing, which says the company was the target of a cyberattack that happened on or around March 26. Personal information potentially compromised includes patient names, dates of birth, Social Security numbers, health insurance information, and medical assessment/medication information. The company is offering credit monitoring through Equifax to all possibly affected people.

Westfield Fire Chief Patrick Egloff sent a follow-up letter to residents to confirm the legitimacy of the Comstar letter, but added that so far, it has not been determined that anyone’s data was actually compromised. He said, however, they do want to err on the side of caution.

If you have any questions, or would like to sign up for the credit monitoring, you are urged to call Comstar’s assistance line at 877-587-4280 Monday through Friday 9:00 A.M. to 9:00 P.M. Eastern.

Egloff says people should not call the Westfield Fire Department, Police Department, or Emergency Dispatch Center with questions about the potential breach.