AUSTIN, Texas -- Fire department officials in Austin, Texas, say one person is unaccounted for following the crash of a small plane into an office building.
Assistant Austin Fire Chief Harry Evans says two people have also been taken to a hospital. Their conditions were not immediately known.
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Law officials identified the pilot of the plane as Joseph Andrew Stack. According to our sister station KEYE-TV, Stack's daughter says he set their house on fire before crashing his plane into the building Thursday morning. KEYE-TV also confirms Stack died in the crash.
Austin Police Chief Art Acevedo says the aircraft was not stolen, as media outlets had previously reported. Acevedo calls the crash "an isolated incident" and there is "no cause for concern" about terrorism.
Authorities are trying to determine if Stack was targeting the Internal Revenue Service. They spoke on condition of anonymity, because the investigation is continuing.
A long, rambling suicide note was posted online that has been attributed to Joseph Stack, where he makes numerous threats toward the IRS.
The IRS in Dallas, Texas, told CNN that the building is a federal IRS outsourced building. It said 199 of its employees work there. The IRS said it thinks all employees are accounted for, but they are checking.
Thick black and gray smoke was billowing out of the second and third stories of the building as fire crews using ladder trucks and hoses battled the fire.
Harry Evans of the Austin Fire Department said firefighters found "heavy fire destruction in and around the second floor ... lots of heat, lots of smoke, lots of fire."
Dozens of windows were blown out of the hulking black building and vehicles traveling on a nearby highway paused to look.
An IRS employee in the building says the impact "felt like a bomb blew off." Peggy Walker says "The ceiling caved in and windows blew in. We got up and ran."
Matty Farney, who saw the plane near some apartments before it crashed, said he thought the pilot was showing off, buzzing the building. Farney called the scene "surreal," saying the ball of flames was as high as the apartments.
The Federal Aviation Administration said the plane was a Piper Cherokee PA-28. The FAA said the plane departed Georgetown Municipal Airport, north of Austin at about 9:40 a.m. and that the pilot did not file a flight plan.
Federal officials say two F-16 fighter jets were launched as a precaution after the crash.
The Associated Press, CNN and KEYE-TV Austin