A suspicious package on the back of a rail car led to the closure of 'C' street in downtown Casper for several hours Thursday morning.

Lt. Brad Wnuk, with the Casper Police Department, says a Burlington Northern Railroad employee spotted the package and called authorities shortly after 9am.

"They found a device that they suspected was possibly an explosive that was on one of the trains while they were doing one of their inspections. That led to a response by bomb technicians, a coordinated unit between the police department and the sheriff's department."

Casper police blocked access to C street from Durbin to McKinley as law enforcement investigated. Casper Fire-EMS and Wyoming Medical were on scene, as well.

He says bomb squad personnel and the FBI determined it was a 6-volt battery with the top sheered off. Wnuk says they suspect is was brought in on the train.

"The train apparently hadn't been in our yard for very long when it was discovered. There was no activity noticed around that car during the time it was here. Speculation is that it was placed on there earlier and transported in to the local train yard."

Authorities reopened the street about 12:30 p.m.