The Port of Baltimore opened a temporary channel on Monday, freeing some tugs and barges that had been trapped by last week's bridge collapse, but officials said wider restoration of commercial shipping remained frustrated by unyielding conditions.

Baltimore's shipping channel has been blocked since a fully loaded container ship lost power and collided with a support column on the Francis Scott Key Bridge last Tuesday, killing six road workers and causing the highway bridge to tumble into the Patapsco River.