The Transportation Security Agency, responsible for monitoring among other people’s safety while embarking on a plane, has reported that a hard drive containing data about approximately 100,000 people is untraceable.

The missing data referred to name, social security number, date of birth, payroll information, financial allotments, and bank account and routing information about 100,000 TSA employees and the disappearance of the HDD was first noticed on May 3. The HDD was missing from a controlled area at the Headquarters Office of Human Capital and it seems that it also contained sensitive data about air-marshals.

TSA immediately reported the incident to senior DHS and law enforcement officials and launched an internal investigation. Later on Friday, TSA notified all employees of the breach on Friday, May 4 after initial inquiries did not lead to the discovery of the hard drive.

It appears that the employees affected by the privacy breach worked with TSA between January 2002 and August 2005. In order to prevent data from being misused, TSA will provide employees and former employees affected by the incident with free credit monitoring for up-to one year. In addition to that, an ID theft insurance of up to $25,000 has been put in place.

Fraud alerts will be installed and identity restoration specialists will complete paperwork and assist current and former employees in the event they are a victim of identity theft.

TSA’s efforts to restore the situation to normal include a tight collaboration with the US Secret Service, in which interviewing key TSA employees and collecting forensic evidence are top priorities.

The TSA said that it “deeply regrets” the incident.