HARDIN • A special education teacher at Calhoun High School was charged in state and federal courts Thursday with making a bomb threat that led to the school being evacuated on Monday.

“This school is going down today. KABOOM!!!!!!!!!!!!!!” Michelle Lynn Smith wrote in a note found Monday in a bathroom at the school, federal authorities said.

Smith, 36, of Jerseyville, was charged in state court Thursday with falsely making a terrorist threat act. Bail was set at $500,000. A federal charge of conveying a false threat followed later Thursday, and she was taken into federal custody where she was held without bail.

She had been held in the Jersey County Jail since Tuesday and was taken into federal custody Thursday.

The school in Hardin was evacuated Monday after someone found a typed letter in a school bathroom indicating there was a bomb in the building. Hardin is about 45 miles northwest of St. Louis along the Illinois River.

According to federal authorities, Smith’s note continued: “Im tired of all the people here. Everyone is going down, the school will b n flames. It is so stupid here. I cant take it ne more. The teachers suck and don’t do ne thing to help u. All that matters is what ur name is. If I had certain names I would not have the truble I do. Don’t matter, this place sucks and will not be here for long. So long and GOOD-BYE!!!!!!!!!”

The letter was discovered about 1 p.m. Monday, and students and teachers were evacuated while police conducted a search. No bomb was found at the school, at 102 Calhoun Drive.

Authorities did not disclose a motive for the threat nor say how they were able to link Smith to the threat.

The high school principal and district superintendent, Kate Sievers, said Smith is a special education teacher at the school. She has been put on paid administrative leave. Sievers declined to comment further.

An online summary of Smith’s teaching experience says she works full time and has 11 years’ experience. Her “about me” page on the high school’s website has been taken down.

Smith faces up to five years in prison and a $250,000 fine on the federal charge.

“Actions such as these cause not only massive wastes of law enforcement resources, but strike fear into the hearts of parents and students alike,” U.S. Attorney Stephen R. Wigginton said in a statement. “Because children should feel safe in their schools, we take these charges very seriously.”