The congressman who represents the Texas district in which a small plane crashed into an office building has been told by federal authorities that the incident was an "intentional attack."

Rep. Michael McCaul (R) appeared on Fox News after he visited the the office building that was hit, which contains Internal Revenue Service (IRS) offices.

"You have an intentional attack that occurred on the federal government today," McCaul said after receiving multiple briefings on the incident.

A Texas software engineer named Joseph Andrew Stack, 53, crashed a single-engine aircraft into a seven story building in Austin, the state capital.

The plane crashed into a seven-story office building in Austin around 10 a.m. local time Thursday.

A suicide note from Stack appeared on the Austin Statesman website Thursday afternoon, which contains some anti-tax outbursts. 

McCaul said that authorities have verified the authenticity of the note and confirmed reports that he lit his house on fire with his family inside before heading to a Georgetown, Texas airport to embark on his flight.

"He apparently lit his house on fire with his wife and daughter in the house, left a suicide note, had a gripe or beef with the IRS," he said.

Some suggested that the act might be an act of terrorism but the White House threw cold water on that theory Thursday afternoon.

White House Press Secretary Robert Gibbs told a pool reporter that that President Barack Obama was briefed on the crash by his top counterterrorism adviser John Brennan, who told him that it does not appear to be terrorism.

Brennan did say, however, that investigators are exploring all possibilities. 

McCaul said that authorities have still not confirmed how many people were injured in the attack and said that "potentially one person may have been killed" aside from the pilot, but said that report has not been confirmed. 

He also praised first responders who conducted "a very heroic rescue effort that potentially avoided what could have been a major loss of life just like we saw with 9/11"

The congressman also said that "we'll certainly look into" security concerns posed by private flights that take off from small, private airports.

Mike Rosen, who is McCaul's communications director, told The Hill earlier Thursday that the congressman was briefed by the Federal Bureau of Investigation (FBI) and local authorities in the morning before heading to the crash scene.

McCaul said he will receive additional briefings following his television appearance. 

A previous version of this post was first published at 1:54 p.m.