Some residents in Clinton, Iowa reported hearing a loud noise coming from the ADM plant early Friday morning, September 27, 2013.
The Clinton County Sheriff's office says it wasn't an explosion.
Many people in the area compared the sound to the sound of a nearby jet engine.
Fire officials on scene have confirmed a semi-truck hit a power line knocking out power to the plant and surrounding areas.
They say the loud noise was ADM's safety vents going off.
They added, there is no hazard to the public.