The Department of Homeland Security stored sensitive data from the nation’s bioterrorism defense program on an insecure website where it was vulnerable to attacks by hackers for over a decade, according to government documents reviewed by The Times.

The data included the locations of at least some BioWatch air samplers, which are installed at subway stations and other public locations in more than 30 U.S. cities and are designed to detect anthrax or other airborne biological weapons, Homeland Security officials confirmed. It also included the results of tests for possible pathogens, a list of biological agents that could be detected and response plans that would be put in place in the event of an attack.

The information — housed on a dot-org website run by a private contractor — has been moved behind a secure federal government firewall, and the website was shut down in May. But Homeland Security officials acknowledge they do not know whether hackers ever gained access to the data.

Read more: Los Angeles Times