According to Austin Fire Deparment spokesperson Michelle DeCrane, emergency crews found the remains of two people inside the building Thursday evening. Their identities have not been confirmed.
The Austin Police Department has turned over the lead investigation to the FBI into a plane crash that sparked a massive fire and evacuations at a Northwest Austin building. Officials are investigating whether the pilot crashed intentionally into the building which houses federal employees.
The crash happened near MoPac and Highway 183 just before 10 a.m. Thursday.
Smoke could be seen pouring from a seven-story building in the Echelon complex -- Echelon 3. KVUE’s Noelle Newton reported most of the windows were blown out. People were evacuated and standing along roads outside the complex. A witness told KVUE that it didn't appear the plane was having any trouble before it crashed, but it was flying very low.
Some witnesses reported that they thought the plane was headed for their building. Witnesses say the impact felt like an explosion.
"This appears to be a singular act to a singular individual," Austin Police Chief Art Acevedo said Thursday afternoon.
Austin police told KVUE Thursday evening a body has been recovered from the building, but it was unclear whether it was the body of the pilot or a person who works in the building and remains unaccounted. Fire officials conducted an office-to-office search. The building houses offices of the Internal Revenue Service. Acevedo says along with the pilot there is only one other person unaccounted for.
Assistant Austin Fire Chief Harry Evans said two people were taken to a hospital with critical injuries. A total of 13 people were treated. EMS officials say most of the injuries were burns or heat inhalation. A spokesperson with University Medical Center Brackenridge says one man -- an adult male -- was treated for smoke inhalation and was released. Another man -- Shane Hill, a criminal investigator with the State Comptrolers Office -- was taken to Brook Army Medical Center in San Antonio with second degree burns to 20-to-25 percent of his body. He's listed in serious but stable condition.
U.S. law enforcement officials say they are investigating whether the crash may have been an intentional act by the pilot.
The officials said authorities are trying to determine if the pilot intentionally targeted nearby office space of the Internal Revenue Service. They spoke on condition of anonymity because the investigation is continuing. A third official said authorities are pursuing reports that the pilot may have been disgruntled with the IRS.
As a precaution, the Colorado-based North American Aerospace Defense Command launched two F-16 aircraft from Houston's Ellington Field, and is conducting an air patrol over the crash area.
The IRS said in a statement that the small plane struck its Austin offices, where 190 of the agency's employees work. Officials say they are still trying to account for all the workers.
Georgetown airport officials say federal officials sealed the airport temporarily. The pilot may have stored his plane in one of the hangars.
A federal law enforcement official has identified the pilot in the plane crash as Joseph Stack, a software developer, and says investigators are looking at an anti-government message on the Web linked to him.
The official said authorities are looking for a motive at Stack's company Web site. The official spoke on condition of anonymity to discuss an investigation still in progress.
The Web site featured a long note dated Thursday denouncing the government and the IRS in particular. It cited the man's problems with the agency.
The long note dated Thursday, February 18 on Stack's Web site says "Violence not only is the answer, it is the only answer" to his past problems with the IRS.
It also says, "I saw it written once that the definition of insanity is repeating the same process over and over and expecting the outcome to suddenly be different. 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."
The letter was removed from the site. A message cites a request from the FBI as part of the reason for removing the letter.
Earlier Thursday about five miles from the crash site, Stack's $232,000 home was engulfed in flames. Two law enforcement officials said Stack had apparently set fire to his home before the crash.
The roof of Stack's red brick home on a tree-lined street in a neighborhood near Metric and Parmer was mostly caved in, and the home's windows were blown out. The garage doors were open and a big pile of debris was inside.
Elbert Hutchins, who lives one house away, said a woman and her teenage daughter drove up to the house before firefighters arrived.
"They both were very, very distraught," said Hutchins, a retiree who said he didn't know the family well. "'That's our house!' they cried 'That's our house!'"
Red Cross spokeswoman Marty McKellips said the agency was treating two people who live in the house. She said they would not be commenting.
"They're remarkably calm but they're clearly distraught. ... They're in need of some mental health assistance and we're providing that," McKellips said.
Federal Aviation Administration spokesman Lynn Lunsford said the pilot took off from Georgetown but didn't file a flight plan. FAA records show that a Piper PA-28 Cherokee with the same tail number as the plane that flew into the building is registered to Joseph A. Stack.
Acevedo cautioned that the reports are hearsay and the investigation is preliminary. He said the plane was not stolen and the crash was not an act of terrorism. Mayor Lee Leffingwell said the situation was contained.
Multiple roads around the building remained shut down, and traffic in the area were diverted. Power was out in the area for much of the day while firefighters fought the flames. Crews at one point were pulled back out from the building of fear the building could collapse, but Austin Fire Chief Rhoda Mae Kerr Thursday afternoon said the building was stable.
It was unclear when the power would be restored and roads reopened.
The National Transportation Safety Board is sending a team to investigate.
The White House says it will await the results of an investigation before deciding whether to call a plane that crashed into a Texas office building an act of terrorism.
White House press secretary Robert Gibbs said Thursday that President Barack Obama is getting updates from local and federal officials. Officials said a software engineer furious with the Internal Revenue Service flew his small plane into an Austin building housing nearly 200 federal tax employees. Obama was briefed on the incident at the White House before departing for political events in Colorado and Nevada.
Gibbs had said earlier that the incident did not appear to be terrorism. When asked specifically if domestic terrorism was a possibility, Gibbs said he does not suspect "somebody like an al-Qaida."
Gov. Rick Perry says with information still "flowing in," he's cautious to relay details he's been told about the crash of a small plane into an Austin office building.
Perry told reporters Thursday in the Houston suburb of Sugar Land that he's hearing "a lot of different story lines" and that Texas law enforcement authorities would assist as appropriate federal officials looking into the crash.
But he says any time an aircraft hits a building, particularly after 9/11, "there is great speculation as to why and how that occurred."
KVUE News has multiple crews on the scene and fanned out across the city. KVUE's Tyler Sieswerda and Terri Gruca are on the air. You can watch complete coverage here.