(Adds comment from Maryland transportation secretary and info about barge hitting bridge in Oklahoma, paragraphs 12-13)
By David Lawder and Joel Schectman
March 30 (Reuters) - Salvage crews worked to lift the first piece of Baltimore's collapsed Francis Scott Key Bridge from the water on Saturday to allow barges and tugboats to access the disaster site, Maryland and U.S. officials said, the first step in a complex effort to reopen the city's blocked port.
The steel truss bridge collapsed early on Tuesday morning, killing six road workers, when a massive container ship lost power and crashed into a support pylon. Much of the span crashed into the Patapsco River, blocking the Port of Baltimore's shipping channel.
Maryland Governor Wes Moore told a news conference that a section of the bridge's steel superstructure north of the crash site would be cut into a piece that could be lifted by crane onto a barge and brought to the nearby Tradepoint Atlantic site at Sparrows Point.
"This will eventually allow us to open up a temporary restricted channel that will help us to get more vessels in the water around the site of the collapse," Moore said.
He declined to provide a timeline for this portion of the clearance work. "It's not going to take hours," he said. "It's not going to take days, but once we complete this phase of the work, we can move more tugs and more barges and more boats into the area to accelerate our recovery."
Workers will not yet attempt to remove a crumpled part of the bridge's superstructure that is resting on the bow of the Dali, the 984-foot Singapore-flagged container ship that brought down the bridge. Moore said it was unclear when the ship could be moved, but said that its hull, while damaged, is "intact."
"This is a remarkably complex operation," Moore said of the effort to clear bridge debris and open the Port of Baltimore to shipping traffic.
The bodies of two workers who were repairing the bridge deck at the time of the disaster have been recovered, but Moore said efforts to recover four others presumed dead remain suspended because conditions are too dangerous for divers to work amid too much debris.
Coast Guard Rear Admiral Shannon Gilreath told reporters that teams from the Coast Guard, the U.S. Navy's salvage arm and the U.S. Army Corps of Engineers said the debris from the Patapsco River's deep-draft shipping channel would have to be removed before the Dali could be moved.
Saturday's operation involves cutting a piece just north of that channel and lifting it with a 160-ton marine crane onto a barge. A larger, 1,000-ton crane also is at the bridge site.