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.

The piece will be brought to Tradepoint Atlantic, the site of the former Bethlehem Steel Mill which is being developed into a distribution center for companies including Amazon.com AMZN.O, Home Depot HD.N and Volkswagen VOWG_p.DE. The facility's port, which sits on the Chesapeake Bay side of the collapsed bridge, is fully operational.

Tradepoint Atlantic did not immediately respond to a request for comment on the company's role in the salvage operation.

Maryland Transportation Secretary Paul Wiedefield said that Tradepoint officials had agreed to allow other ships to unload vehicles at the facility's deepwater dock to be prepared for shipment to dealers.

In Oklahoma, authorities said on Saturday they shut down a portion of U.S. highway 59 near Sallisaw after a barge struck a bridge over the Arkansas River. There were no immediate reports of injuries, according to media reports, and officials would be conducting inspections of the bridge.

Five days after the tragedy in Maryland, the jobs of some 15,000 people whose work revolves around daily port operation are on hold. While logistics experts say that other East Coast ports should be able to handle container traffic, Baltimore is the largest U.S. port for "roll-on, roll-off" vehicle imports and exports of farm and construction equipment.

U.S. Senator Chris Van Hollen of Maryland said the Small Business Administration has approved the state's request for a disaster declaration that allows small firms affected by the disaster to apply for emergency low-interest loans of up to $2 million through the end of 2024.

The federal government on Thursday awarded Maryland an initial $60 million in emergency funds to clear debris and begin rebuilding the Key Bridge, an extraordinarily fast disbursement. President Joe Biden has pledged that the federal government would cover all costs of removing the debris and rebuilding the bridge