The 155 foot long towboat Jeffrey G with its string of 30 barges allided with the old bridge over the Mississippi River at Viscksburg, Mississippi.  The Jeffrey G was heading downriver when it struck the bridge with several barges breaking free.  One barge loaded with grain sank while several other barges floated downriver.  Other towboats were able to recover the barges that broke free.  No reports of injuries. Reports state the barges did not contain any hazardous materials.  The Coast Guard has launched an investigation into the incident.