A series of bomb threats directed at an Amtrak train on July 6 stranded about 300 passengers, according to CNN.
Running a combined route from Seattle to Portland, Ore., to Chicago, the train was stopped in Portage, Wis., about 80 miles northwest of Milwaukee.
The 282 passengers and crewmembers were held at a nearby elementary school for questioning while authorities searched the train.
Police found that some passengers had fireworks in their luggage, but no other explosives were discovered.
The train resumed its trip more than six hours after it was stopped.