AUSTIN, Texas — Why Andrew Joseph Stack III flew his plane into an office building isn't a mystery.
"I am finally ready to stop this insanity. Well, Mr. Big Brother IRS man, let's try something different; take my pound of flesh and sleep well," he wrote.
That's the end of a lengthy missive that Stack, a computer software engineer, finished at 1:42 a.m. (CST) Thursday and posted on a company Web site.
Hours later, he set fire to his red brick home in Austin. He then drove to the municipal airport, climbed into his single-engine plane and took off about 9:45 a.m. He had no flight plan but did have a target: a seven-story office building in northwest Austin that houses about 190 Internal Revenue Service workers, many of them civil and criminal investigators.
He slammed his plane into the building, killing himself and one other person in the building. "Nothing changes unless there is a body count," he wrote.
Thirteen people on the ground were injured, two of them seriously, in the crash of the single-engine Piper PA-28 and subsequent fire, which initially inspired fears of a terrorist attack and drew nationwide attention.
Early on, when it seemed possible the crash could be an act of foreign terrorism, federal officials scrambled two F-16s from Houston's Ellington Field.
But within hours of the crash, before even the identity of the pilot had been confirmed, officials ruled out any connection to terror groups or causes.
In the six-page, 3,000-word statement signed "Joe Stack (1956-2010)," Stack focused his rage at the U.S. tax system, accusing the IRS of damaging his career and the nation's political system.
"I knew Joe had a hangup with the IRS on account of them breaking him, taking his savings away," said Jack Cook, the stepfather of Stack's wife, in a telephone interview from his home in Oklahoma. "And that's undoubtedly the reason he flew the airplane against that building. Not to kill people, but just to damage the IRS."
Stack felt the federal government — especially its tax code — robbed him of his savings and destroyed his career while allowing corrupt executives to walk away with millions.
But in place of the typical portrait of a terrorist driven by ideology, Stack was described by others as generally easygoing, a talented amateur musician.
Stack's friends say they knew him as a fellow country rocker and bandmate who recorded with them in Austin's vibrant music scene. They recalled a quiet father who visited Norway every year to see his daughter and grandchildren. They never heard Stack talk about politics, about taxes, about the government.
"I read the letter that he wrote. It sounded like his voice but the things he said I had never heard him say," said Pam Parker, an Austin lawyer whose husband was one of Stack's bandmates. "He didn't rant about anything. He wasn't obsessed with the government or any of that. . . . Not a loner, not off in a corner. He had friends and conversation and ordinary stuff."
There was nothing ordinary about Stack's antigovernment screed. Part-autobiographical, the rambling letter references a divorce and some failed business ventures in California.
Stack refers to several disputes with the IRS that cost him more than $40,000 and "10 years of my life." He twice started software companies in California that ultimately were suspended by the state's Franchise Tax Board. Stack listed himself as chief executive officer of both.
The tipping point for Stack appears to be a recent audit, and the discovery of nearly $13,000 in unreported income.
"I know I'm hardly the first one to decide I have had all I can stand," Stack wrote. "But I also know that by not adding my body to the count, I insure nothing will change."
Stack wrote that he spent months on the six-page diatribe in hopes it would be therapeutic.
The disputes with the IRS were apparently never discussed among friends.
"I don't know what to base his madness on," said Michael Cerza, who played drums, piano and trumpet with Stack in the Billy Eli Band. "It must have been lurking beneath the surface."
Stack attended Harrisburg Area Community College from 1975-77 but did not graduate. Before that, he graduated from Milton Hershey School in Hershey.
Stack later married, moved to California and had a daughter who grew up to marry a Norwegian pilot. Parker said Stack went to Norway to visit her and his grandchildren each year.
According to his letter, he moved to Austin sometime after 2001. The divorced bass guitar and piano player met Sheryl, a pianist who gives lessons, through friends who thought their mutual passion for music made them a match. Cerza said he recently received a group e-mail in which Stack invited friends to one of his wife's piano recitals.
"Joe was very straight — didn't drink or smoke. He was intelligent, concerned about all the stuff normal people are concerned about," Cerza said. "He did not strike me as having any angular edges at all. He would be the guy who would choose not to say anything in a group of people."
The Stacks' home was set ablaze Thursday morning, burning to the ground as Sheryl and the couple's daughter, 12, watched from the street.
Elbert Hutchins, who lives one house away, said the house caught fire about 9:15 a.m. He said the woman and her daughter drove up to the house before firefighters arrived.
"They both were very, very distraught," he said, adding that Sheryl Stack cried, "That's our house!" The woman and her daughter went to another neighbor's home and remained inside.
This report contains information from the Dallas Morning News, Associated Press and New York Times.