Investigation Summary
The sequence of events began at approximately 09:15 CST when Andrew Joseph Stack III set fire to his home in North Austin. He then drove to Georgetown Municipal Airport, where he kept his Piper Dakota. Stack took off at 09:44, initially climbing to 4,800 feet while maintaining normal radio communications with air traffic control. His final transmission to a controller was, "Eight niner delta thanks for your help have a great day." Shortly after, he began a high-speed descent toward the Echelon I building, a four-story office complex located at 9430 Research Boulevard. The IRS occupied the top three floors of the building. Witnesses observed the aircraft flying low and fast before it struck the building's southeast face between the first and second floors at 09:58. The impact triggered a massive fireball fueled by the aircraft's nearly full fuel tanks. The building suffered significant structural damage and was eventually gutted for reconstruction. First responders, including a hazardous materials team that happened to be training nearby, initiated search and rescue operations; meanwhile, a glass worker used a ladder from his truck to rescue six people trapped on the second floor.
Final Conclusions
The NTSB released its final report on December 27, 2010, concluding that the pilot intentionally flew the airplane into the building. Because the crash was a deliberate criminal act rather than an accident resulting from mechanical failure or pilot error in the traditional sense, the FBI held primary jurisdiction. The investigation confirmed the pilot's motive through a suicide note found on his website, which expressed extreme hostility toward the IRS following years of tax disputes and business failures. The official cause is recorded as an intentional suicide attack.
Photographic Evidence (1)
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Piper PA-28-236 Dakota (MSN 28-7911227)
A four-seat, single-engine light aircraft. The NTSB found the flaps in the fully retracted position, consistent with a high-speed intentional impact. The aircraft was destroyed by impact and post-impact fire.
Air Traffic Control Radar
Radar tracked the aircraft from its departure at Georgetown until it descended below 1,000 feet near the target building, showing a descent from 4,800 feet starting at 09:54.
Interesting Facts
- 01The pilot, Andrew Joseph Stack III, was the sole occupant of the aircraft and died in the crash.
- 02IRS manager Vernon Hunter was killed inside the building, bringing the total fatalities to two.
- 03Thirteen people were injured in the building, two of them critically.
- 04The aircraft was a Piper PA-28-236 Dakota, registration N2889D, serial number 28-7911227.
- 05NORAD scrambled two F-16 fighter jets from Houston as a standard precautionary measure.
- 06A civilian glass worker, Robin DeHaven, rescued six people from the building using his truck's extension ladder.
- 07The building was so heavily damaged it required a complete gutting and reconstruction.
- 08The IRS spent over $38.6 million in the aftermath for recovery and nationwide security enhancements.
Safety Actions & Advisories
Building Protection Review
Following the attack, members of the U.S. House of Representatives Homeland Security Committee initiated discussions on how to better protect federal buildings from small aircraft attacks.
Known Controversies & Unanswered Questions
Terrorism Classification
Reference ↗There was public and political disagreement over whether to classify the attack as domestic terrorism. While some members of Congress labeled it as such, the FBI and DHS initially investigated it as a criminal assault on federal officers, citing the lack of links to organized terrorist groups.