AUSTIN -- Investigators want to know if today's fiery crash of a small plane into an Austin building that houses the IRS -- was intentional.
The Associated Press reports authorities are trying to determine if the pilot targeted the tax agency.
Assistant Austin Fire Chief Harry Evans says one person is missing and two people were taken to a hospital. Their conditions and identities weren't immediately known.
The crash sent workers fleeing as ceilings crumbled, windows shattered and flames shot out of the building.
Thick black and gray smoke was billowing out of the second and third stories.
Federal Aviation Administration spokesman Lynn Lunsford says the pilot didn't file a flight plan.
IRS worker Peggy Walker was at her desk when the plane crashed.