A high school teacher in Illinois was arrested after allegedly making a bomb threat at school, The Associated Press reported.
Michelle L. Smith, 36, was charged in Calhoun County with falsely making a terrorist threat and jailed on $500,000 bond on Tuesday.
According to authorities, Smith is accused of leaving a typed letter in a Calhoun County High School on Monday indicating a bomb was planted on school grounds.
Students and faculty were immediately evacuated. However, no bomb was discovered.
The next day, Smith was detained. Investigators did not disclose how they connected the teacher to the note.
It is unknown if she has legal representation and the school district has not commented on the issue.
Smith, a special education teacher, has been teaching for 11 years. Her "about me" section on the school's website has been taken down since her arrest, the St. Louis Post-Dispatch said.
On Thursday, East High School in Salt Lake City, Utah was placed on lockdown after two threats were made to the school.
Salt Lake City Police Detective Cody Lougy told the Salt Lake Tribune officers responded to two 911 calls -- one being a bomb threat and one report of shots fired.
Lougy said both calls were made by the same person. By 10:20 a.m., the lockdown was lifted after the calls appeared to be a joke.
"It appears this is just a prank," Lougy said.
No injuries were reported and there was no information on any suspects or arrests.
Also on Thursday, a student at Yankton High School in South Dakota was charged with threatening the school.
Tanner Termansen, 18, was arrested on Tuesday and later charged with falsely reporting a bomb threat.
Termansen was also suspended from school, officials said.
