Incident Summary:

08/04/2017: A package delivered to an Internal Revenue Service (IRS) office made employees sick in Kansas City, Missouri, United States. At least 10 people reported being ill, which included vomiting and nausea. No group claimed responsibility for the attack.



United States

North America

region/u.s. state:


Kansas City

Attack Information
Type of Attack (more) Unarmed Assault
Successful Attack? (more) Yes
Target Information (more)
Target Type: Government (General)
Name of Entity United States Department of Treasury
Specific Description Internal Revenue Service (IRS) Employees
Nationality of Target United States
Additional Information
Hostages No
Ransom No
Property Damage No
Weapon Information
Type Sub-type
Chemical Poisoning
Weapon Details
An unidentified toxic substance, which smelled like ammonia, was used in the attack.
Additional Information
Suicide Attack?No
Part of Multiple Incident?No
Criterion 1 (more) Yes
Criterion 2 (more) Yes
Criterion 3 (more) Yes
Doubt Terrorism Proper (more) No
Perpetrator Group Information
Group Name Claimed Responsibility
Unknown No
Perpetrator Statistics
Number of Perpetrators Unknown
Number of Captured Perpetrators 0
Casualty Information
Total Number of Casualties 0 Fatalities / 10 Injured
Total Number of Fatalities 0
Number of U.S. Fatalities 0
Number of Perpetrator Fatalities 0
Total Number of Injured 10
Number of U.S. Injured 10
Number of Perpetrators Injured 0
"IRS building staffers sickened by package," Journal-Gazette, August 5, 2017.
"Feds investigate suspicious package that sickened people at Kansas City IRS building," Chicago Tribune, August 4, 2017.
"Suspicious package at IRS building in Kansas City leaves 10 employees sick," CBS News, August 4, 2017.