Her comments come a day after A. Joseph Stack III, a software engineer, crashed his plane into IRS offices in Austin, Texas,, and apparently left behind an irate anti-government manifesto detailing his financial difficulties and tax problems.
"I just thought it was unfair how an angry individual took out his anger on innocent people," Elva Liando, an IRS employee who works on the second floor, told CBS' "The Early Show" Friday.
"I didn't think it was an accident," she said.
Liando said she immediately fled the building upon the plane's impact and said people outside the office seemed in shock.
Fellow IRS employee, Richard Lee, declined to express his feelings about the crash: "I really have no comment about what somebody did because they were mad about the IRS."
The fiery crash wasn't the first time a protester went after an Austin IRS building.
In 1995, Charles Ray Polk plotted to bomb the IRS Austin Service Center. He was released from prison in October of 2009.
A U.S. law official said investigators were looking at an anti-government message on the Web linked to him. The Web site outlines problems with the Internal Revenue Service and says violence "is the only answer."
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The tax protest movement has a long history in the U.S. and was a strong component of anti-government sentiments that surged during the 1990s.
That wave culminated in the April 1995 bombing of a federal building in Oklahoma City that killed 168 people. Several domestic extremists were later convicted in the plot.