Two thousand patients of Westerly (RI) Hospital are at risk of identity theft after their names, Social Security numbers, and medical records appeared on a public Web site, The Boston Globe reports.

The organization claims it does not know how the security breach occurred and said the incident only affected patients seen on certain days in January. A patient discovered the breach after searching for a phone number online.

Westerly Hospital does not know how long the information was available on the Internet. The FBI is investigating the case.