CHICAGO (CBS) — An anti-theft device, usually placed on clothes, brought the CTA Blue Line to a standstill Monday.

It all started during rush hour at the Logan Square station in the 6200 block of North Milwaukee.

blue line stopped Anti Theft Device Thrown On Tracks Shut Down Logan Square Blue Line Station

Police say someone tossed a device, used in retail stores to prevent theft, onto the train tracks.

Trains were stopped, forcing commuters to use the bus while police investigated.