The fallen Francis Scott Key Bridge in Baltimore is pictured on Sunday. Mike Pesoli/Associated Press

BALTIMORE — The U.S. Coast Guard has opened a temporary, alternate channel for vessels involved in clearing debris from the collapsed Francis Scott Key Bridge in Baltimore, part of a phased approach to opening the main shipping channel leading to the vital port, officials said Monday.

Crews are undertaking the complicated work of removing steel and concrete at the site of the bridge’s deadly collapse after a container ship lost power and crashed into a supporting column. On Sunday, dive teams surveyed parts of the bridge and checked the ship, and workers in lifts used torches to cut above-water parts of the twisted steel superstructure.

Officials said the temporary channel is open primarily to vessels that are helping with the cleanup effort. Some barges and tugs stuck in the Port of Baltimore since the collapse are also scheduled to pass through the channel.

Authorities believe six workers plunged to their deaths in the collapse, including two whose bodies were recovered last week.

Maryland Gov. Wes Moore said at a Monday afternoon news conference that his top priority is recovering the four remaining bodies, followed by reopening shipping channels to the port. He said he understands the urgency but that the risks are significant. He said crews have described the mangled steel girders of the fallen bridge as “chaotic wreckage.”

“What we’re finding is it is more complicated than we hoped for initially,” said U.S. Coast Guard Rear Admiral Shannon Gilreath.

Moore said crews used a large crane to lift a 200-ton span of the bridge, a task that took 10 hours. He said the piece was considered a “relatively small lift” in the grand scheme of the recovery effort, which he called enormous.

Moore said crews would lift another 350-ton piece from the bridge later Monday as weather allows.

Officials earlier said the temporary channel would have a controlling depth of 11 feet, a horizontal clearance of 264 feet and a vertical clearance of 96 feet.

“This marks an important first step along the road to reopening the port of Baltimore,” Capt. David O’Connell, the federal on-scene coordinator of the response, said in a statement Monday. “By opening this alternate route, we will support the flow of marine traffic into Baltimore.”

Two additional larger channels are planned as more debris is removed from the waterway. Officials declined to provide a projected timeline for those channels being opened.

Meanwhile, the ship remains stationary, and its 21 crew members remain on board for the foreseeable future, officials said. Twenty of them are from India, and one is from Sri Lanka, said Will Marks, a spokesperson for the crew. He said they’re currently busy maintaining the ship and cooperating with investigators from the National Transportation Safety Board and the U.S. Coast Guard.

Marks said it’s unclear how long the crew will remain on board.

Officials in Baltimore said the crew has plenty of supplies. They said parts of the ship that were damaged in the crash didn’t include the crew’s living quarters or kitchen.

President Biden will visit the collapse site Friday, White House press secretary Karine Jean-Pierre announced Monday. He will meet with state and local officials and get an “on-the-ground look” at federal response efforts, Jean-Pierre said.

Moore said he expects the president will leave with a better understanding of the task at hand.

“He’s going to see the fact that we have a ship that is almost the size of the Eiffel Tower, that weighs about as much as the Washington Monument, that’s in the middle of the Patapsco River,” Moore said. “He’s going to see a bridge that has been in existence since I was alive – I don’t know what that skyline looks like without the Key bridge – and he is going to come and he’s going to see it sitting on top of a ship.”

Also Monday, the Small Business Administration opened two centers in the area to help companies get loans to assist them with losses caused by the disruption of the bridge collapse.

Yvette Jeffery, a spokesperson for the agency’s disaster recovery office, said affected businesses can receive loans for as much as $2 million. She said the effects could range from supply-chain challenges to decreased foot traffic in communities that depended heavily on the bridge.

The bridge fell as the cargo ship Dali lost power March 26 shortly after leaving Baltimore on its way to Sri Lanka. The ship issued a mayday alert, which allowed just enough time for police to stop traffic, but not enough to save a roadwork crew filling potholes on the bridge.

Two workers survived, two bodies were found in a submerged pickup, and four more men are presumed dead.

The Dali is managed by Synergy Marine Group and owned by Grace Ocean Private Ltd., both of Singapore. Danish shipping giant Maersk chartered the Dali.

Synergy and Grace Ocean filed a court petition Monday seeking to limit their legal liability, a routine but important procedure for cases litigated under U.S. maritime law. A federal court in Maryland will ultimately decide who is responsible and how much they owe.

The filing seeks to cap the companies’ liability at roughly $43.6 million. It estimates that the vessel itself is valued at up to $90 million and was carrying freight worth over $1.1 million in income for the companies. The estimate also deducts two major expenses: at least $28 million in repairs and at least $19.5 million in salvage.

Officials are trying to determine how to rebuild the major bridge, which was completed in 1977. It carried Interstate 695 around southeast Baltimore and became a symbol of the city’s working-class roots and maritime culture.

Congress is expected to consider aid packages to help people who lose jobs or businesses because of the prolonged closure of the Port of Baltimore. The port handles more cars and farm equipment than any other U.S. facility.

Baltimore Mayor Brandon Scott said it won’t happen overnight, but the city and its port will recover.

“It will be likely a very hard road,” he said. “But we here in Baltimore are built with grit … and we’re going to show the world what that truly means.”

Contributing to this report were Associated Press journalists Mike Pesoli in Baltimore; Jeffrey Collins in Columbia, South Carolina; Sarah Brumfield in Washington.