(CNN) -- A teen beauty queen in Utah and three others were arrested Saturday morning for allegedly making and throwing bombs that an explosives investigator says could have killed someone. Kendra Gill, Bryce Stone, Shanna Smith and John Reagh -- all 18 -- admitted to buying the materials for the explosives, making the devices and throwing them from a vehicle, according to a Salt Lake County Sheriff's Office probable cause statement that CNN obtained. Gill was crowned Miss Riverton in June, and was set to compete for the Miss Utah title, CNN affiliate KUTV reported. Investigators began getting calls late Friday night from Riverton residents who heard "loud pops," said Capt. Clint Mecham of the Unified Fire Authority which is investigating the case.
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Kendra Gill and 3 other 18-year-olds accused of making, throwing explosive devices
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Devices had potential to maim or kill, Fire Authority captain says
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One teen told investigators that they were "pranking," probable cause document says
One of the witnesses identified @placeholder as the driver and gave investigators his address.