The bridge collapsed within seconds on March 26 after being struck by the cargo ship Dali, which lost power shortly after leaving Baltimore, bound for Sri Lanka. The ship issued a mayday alert with just enough time for police to stop traffic, but not enough to save a roadwork crew filling potholes on the bridge. Authorities believe six workers plunged to their deaths in the Patapsco River; two bodies have been recovered so far. Two others survived.

The U.S. Army Corps of Engineers announced a “tentative timeline” Thursday, saying in a news release that it expects to open a limited access channel to the port within the next four weeks measuring some 280 feet wide by 35 feet deep (85 meters by 11 meters). The channel would support one-way traffic in and out of the port for barge container service and some vessels that move automobiles and farm equipment to and from the port.

The USACE said it is aiming to reopen the permanent, 700-foot-wide by 50-foot-deep (213 meter by 15 meter) federal navigation channel by the end of May, which would restore port access to normal capacity.

“A fully opened federal channel remains our primary goal, and we will carry out this work with care and precision, with safety as our chief priority,” Lt. Gen. Scott Spellmon, USACE commanding general said in the news release.

Spellmon acknowledged the timelines are “ambitious” and may still be impacted by adverse weather or “changes in the complexity of the wreckage.”

The announcement came on the eve of a scheduled visit by President Joe Biden, who is to view the collapse site and meet with relatives of the victims Friday.

White House press secretary Karine Jean-Pierre said Biden also will receive an operational update from U.S. Coast Guard and Army Corps of Engineers officials.

On Thursday, Isabella Casillas Guzman, who heads the U.S. Small Business Administration, visited Baltimore to meet with business owners, along with state and local leaders. Guzman said a federal program offering loans to small businesses hurt by the bridge collapse has received 500 applications so far.

Businesses involved in transportation and supply chain logistics will likely suffer most in the short term, she said, but long-term ripple effects will be widespread.

“It’s a full range of impact,” she said following a roundtable discussion at an office in Baltimore that was opened in recent days to assist business owners affected by the collapse.

Baltimore’s port handles more cars and farm equipment than any other similar facility in the country, and the disaster has created logistical problems up and down the East Coast.

The Maryland Senate unanimously approved a bill Wednesday night authorizing the governor to use the state’s rainy day fund to help unemployed port employees. That sends the bill to the Maryland House, which could approve the bill this week.

The Norwegian shipping firm Wallenius Wilhelmsen, which has a hub in Baltimore, said it estimates its own losses at between $5 million and $10 million from the port closure. One of its ships is among several currently stuck in Baltimore’s harbor.

Crews are working to clear the steel wreckage and recover the remaining bodies, something made even more difficult by recent bad weather. They have opened two temporary channels meant primarily for vessels involved in the cleanup.

But the water is so murky that salvage divers can’t see more than one to two feet in front of them, Gov. Wes Moore said at a news conference Thursday afternoon. Each diver is now paired with an operator who uses three-dimensional drawings and other tools to guide them in a “buddy system,” he said.

U.S. Coast Guard Rear Admiral Shannon Gilreath said there are seven commercial vessels stuck in the port with their crews on board. The ships will not be able to leave until a temporary channel is opened that is deep enough for them to get out.