As part of its oversight of the nation's homeland security, the Committee has held hearings, conducted investigations, written reports, and drafted legislation on the threat of biological, chemical, and nuclear weapons. The Committee has investigated the nation's preparedness for a terrorist attack with a dirty bomb and found it wanting. The Committee's investigation into the mismanagement of efforts to build a second generation nuclear detection network to prevent WMD from being smuggled into the country resulted in cancellation of the program. The Committee actively oversaw the government response to the H1N1 influenza (swine flu) pandemic and held four hearings on the subject in 2009. The Committee also has worked over the years to ensure the security of the nation's chemical facilities against terrorist attack.