MISSOULA, Mont. -

A Washington state woman pleaded not guilty to charges for allegedly setting fire to a Missoula hospital's bathroom.

Last month deputies pulled Thompson over for erratic driving on Interstate 90. She told the deputy the man in the passenger seat punched her in the stomach and she was in pain. The deputy said he took her to the hospital to get a blood test after he noticed she had signs of methamphetamine use.

According to the complaint Thompson refused the test, but asked to use the bathroom in the Emergency Room at St. Patrick Hospital. After Thompson had been in there for a while deputies say they found she allegedly started a fire in the bathroom with a lighter.

Deputies say she told them she was trying to kill herself.

In Missoula County District Court Tuesday, she pleaded not guilty to felony arson, and two misdemeanors for operating a motor vehicle while under the influence of drugs and criminal possession of drug paraphernalia.