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Five students and a teacher were injured at a Michigan high school on Monday after a 16-year-old student accidentally detonated a homemade explosive device in class, authorities said.
Officers with the Newaygo Police Department were dispatched to Newaygo High School just before 9 a.m. for a report of an "explosion," according to a press release from Newaygo Public Schools.
"A 16-year-old student brought a homemade explosive device into the classroom," the release said. "The device detonated in the classroom, injuring the 16-year-old and four additional classmates."
An additional statement from the Michigan State Police said a preliminary investigation indicated that the detonation was accidental.
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The 16-year-old was hospitalized with moderate to severe injuries, while the others were transported to the hospital by their parents with minor injuries. The teacher present in the classroom at the time of the explosion also sought treatment at the hospital, the release said.
© GettyThe school superintendent said the 16-year-old student displayed "a serious lack of judgment"
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Peggy Mathis, superintendent of Newaygo Schools, told MLive that the explosion was "not an attack or designed to be something malicious, but a serious lack of judgment."
A spokesperson for Michigan State Police told Fox affiliate WXMI the device appears to have been homemade, and was not a firework as the school district previously posted on social media.
The release said that high school students were dismissed for the rest of the day, and that all schools in the county went under lockdown until it was determined there was no further threat to students.
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"The investigation continues into what kind of material was involved in the explosion and the circumstances contributing," the release said. "This is believed to be an isolated incident and remains under investigation."