Incident Summary:

08/24/2009: On Monday morning, in San Mateo, California, United States, at Hillsdale High School, authorities arrested a 17 year old boy armed with ten pipe bombs, a two foot sword and a chainsaw, after he threw two of the lightened pipe bombs into a hallway near the school library. He intended to kill people with the bombs and slaughter survivors with a chainsaw. No injuries or causalities were reported and minor damage was caused to the building. No group claimed responsibility.



United States

North America

region/u.s. state:


San Mateo

Location Details:
The bombing took place at Hillsdale High School.

Attack Information
Type of Attack (more) Bombing/Explosion
Successful Attack? (more) Yes
Target Information (more)
Target Type: Educational Institution
Name of Entity
Specific Description A high school was targeted in the attack.
Nationality of Target United States
Additional Information
Hostages No
Ransom No
Property Damage Yes
Extent of Property Damage Minor (likely < $1 million)
Value of Property Damage Unknown
Weapon Information
Type Sub-type
Explosives Pipe Bomb
Melee Knife or Other Sharp Object
Weapon Details
Ten pipe bombs, a two foot sword and a chainsaw was used in the attack.
Additional Information
Suicide Attack?No
Part of Multiple Incident?No
Criterion 1 (more) No
Criterion 2 (more) Yes
Criterion 3 (more) Yes
Doubt Terrorism Proper (more) Yes
Alternate Designation (more) Other Crime Type
Perpetrator Group Information
Group Name Claimed Responsibility
Unknown No
Perpetrator Statistics
Number of Perpetrators 1
Number of Captured Perpetrators 1
Casualty Information
Total Number of Casualties 0 Fatalities / 0 Injured
Total Number of Fatalities 0
Number of U.S. Fatalities 0
Number of Perpetrator Fatalities 0
Total Number of Injured 0
Number of U.S. Injured 0
Number of Perpetrators Injured 0
Contra Costa Times,"All Safe After Chaos- Former Student Arrested Still Strapped with Bombs," (August 25, 2009).
China View,"Teenager Arrested in U.S. High School Explosion,", (June 25, 2009).