Mississippi River barge traffic could reopen Friday at the earliest, government officials said on Wednesday, a day after a barge struck a railroad bridge at Sabula, Iowa, forcing the closure of a two-mile (3.2 km) stretch of the country's busiest waterway. The U.S. Coast Guard was investigating damage to the railroad bridge owned by Canadian Pacific Railroad Ltd while the U.S. Army Corps of Engineers was traveling to the site to survey the waters for any debris. "Currently the river is closed to vessel traffic. It will be closed through Friday at least," said Mike Reed, chief of prevention for the Coast Guard's upper Mississippi River sector. A vessel towing 15 barges upriver hit the bridge on Tuesday, damaging a portion of the protective pier.