Prior to the crash, Stack had posted a suicide note to his website, expressing his disillusionment with corporations and government agencies such as the IRS.

Andrew Joseph Stack III (August 31, 1956 – February 18, 2010) lived in the Scofield Farms neighborhood in North Austin, and worked as an embedded software consultant.

[14] Stack obtained a pilot's certificate in 1994 and owned a Velocity Elite XL-RG plane, in addition to the Piper Dakota (aircraft registration N2889D) he flew into the Echelon building.

"[27] About ten minutes later, his plane descended and collided at full speed with Echelon I, a building containing offices for 190 IRS employees, resulting in a large fireball and explosion.

[13][30][31][32][33] The HTML source code of the web page shows the letter was composed using Microsoft Word starting two days prior, February 16, at 19:24Z (1:24 p.m.

The capitalist creed: From each according to his gullibility, to each according to his greed.Vernon Hunter, a 68-year-old Revenue Officer Group Manager for the IRS, was killed in the incident along with Joseph Stack.

Debris from the crash reportedly shattered the windshield of a car being driven on the southbound access road of Highway 183 in front of the building.

[3] Another driver on the southbound access road of Highway 183 had his windows and sunroof shattered during the impact, and had debris fall inside his car, yet escaped uninjured.

[6][37] Robin DeHaven, a glass worker and former combat engineer for the United States Army, saw the collision while commuting to a customer's house for his job, and used the extension ladder on his truck to rescue six people from the 2nd floor of the building.

[38] By coincidence, the Travis County Hazardous Materials Team — an inter-agency group of firefighters from outside the City of Austin — had just assembled for training across the freeway from the targeted building, observed the low and fast flight of Stack's plane, and heard the blast impact.

[10] An additional $1,236,634 was spent on a security risk assessment to be performed by the private Georgia based logistical and engineering services firm Unified Consultants Group, Inc. A July 25, 2012 audit, released shortly after the incident cost analysis, performed by the Treasury Inspector General for Tax Administration, determined that the contract was mismanaged by the IRS.

[44] The United States Department of Homeland Security issued a statement saying that the incident did not appear to be linked to organized international terrorist groups.

[23] White House spokesman Robert Gibbs reaffirmed what Homeland Security said, and that President Barack Obama was briefed on the incident.

[45] The North American Aerospace Defense Command (NORAD) launched two F-16 fighter aircraft from Ellington Airport in Houston, Texas, to conduct an air patrol in response to the crash.

"[46][47] Several groups supporting Stack on the social networking website Facebook appeared following the incident and the news of the accompanying manifesto.

Georgetown University Professor Bruce Hoffman stated that for this to be considered an act of terrorism, "there has to be some political motive and it has to send a broader message that seeks some policy change.

She also stated that Stack could not be connected with the Tea Party movement, but argued that the incident "should inject a bit of caution into the anti-government flame-throwers on the right.

[55] In an interview with ABC's Good Morning America, Joe Stack's adult daughter, Samantha Bell, who now lives in Norway, stated initially that she considered her father to be a hero, because she felt that now people might listen.

[58] Former Iowa congressman Steve King (R-Iowa) has made several statements regarding Stack including, I think if we'd abolished the IRS back when I first advocated it, he wouldn't have a target for his airplane.