Four 18-year-old freshmen at Michigan State University have been charged after a three-inch mortar exploded in an East Lansing yard.
Campus police spokeswoman Florene McGlothian-Taylor says the device was powerful enough to kill someone.
The mortar was detonated Sunday. Two additional devises were found in a car after the students were arrested.
Olivia Hudson, Sasha Savage, Darby Dudley and Nikolai Wasielewski are charged with placing explosives and causing property damage. They also are charged with possession of bombs with unlawful intent to cause property damage.
The students were released Monday following a hearing in East Lansing District Court.