BALTIMORE — A tentative timeline has been released for how soon authorities believe they can reopen crucial commercial shipping channels that have been blocked since last week’s bridge collapse in Baltimore.

President Joe Biden also plans to visit the port city. And federal and state authorities are ramping up efforts to soften the economic blow to businesses and residents who work in Maryland’s maritime industry.

Here’s what we know about as cleanup efforts gets underway:

WHAT’S THE TIMELINE FOR CLEARING THE WRECKAGE?

Engineers said Thursday that they expect to restore navigation in and out of the Port of Baltimore by the end of this month.

The Francis Scott Key Bridge collapsed within seconds on March 26 after being struck by the cargo ship Dali, which lost power shortly after leaving Baltimore.

The U.S. Army Corps of Engineers said it expects to open a limited access channel in the next four weeks. It would support barge container service and some vessels that move automobiles and farm equipment to and from the port.

Meanwhile, the agency is aiming to reopen a permanent navigation channel by the end of May, which would restore port access to normal capacity.

Lt. Gen. Scott Spellmon, USACE commanding general, has acknowledged the timelines are “ambitious” and may still be impacted by adverse weather or “changes in the complexity of the wreckage.”

Divers are also hoping to recover the bodies of the six construction workers who died. Weather conditions and the river’s murky water have been making the task difficult and so far only two of their bodies have been recovered.

WHAT ARE PRESIDENT BIDEN’S PLANS?

Biden is expected to get a firsthand look Friday at efforts to clear away the hulking remains of the massive span.

The president also plans to meet with the families of the construction workers.

Eight workers — all immigrants from Mexico, Guatemala, Honduras or El Salvador — were filling potholes on the span. Only two of them survived the crash.

The White House announced Friday that it’s asking Congress to authorize the federal government to cover 100% of the collapsed bridge cleanup and reconstruction costs, rather than seeking funding through a separate, supplemental funding request.

Authorization is likely no slam-dunk in Congress. And funding questions carry political implications as Biden squares off with former President Donald Trump in November’s election.

HOW ARE AFFECTED BUSINESSES AND WORKERS GETTING HELP?

Isabel Casillas Guzman, the administrator of the U.S. Small Business Administration, visited Baltimore on Thursday to highlight a low-interest loan program that’s available to affected businesses.

The program has received 500 applications, Guzman said, and the funds could start being distributed within about two weeks.

The loans will help keep companies afloat as Baltimore’s vital port remains closed to most maritime traffic. Guzman said businesses involved in transportation and supply chain logistics will likely suffer the most in the short term, but the long-term ripple effects will be widespread.

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.

WHAT SAFETY MEASURES WERE IN PLACE FOR THE CONSTRUCTION WORKERS WHO DIED?

The deaths of the construction workers have raised questions about whether the company they worked for took proper precautions, including keeping a safety boat nearby that might have been able to warn them at least a few seconds before impact.

Federal regulations require construction companies to keep such boats, commonly known as skiffs, on hand whenever crews are working over waterways, safety experts told The Associated Press. There is no indication that the Brawner construction company had a rescue boat on the water or ready to be launched as the bridge fell.

Even if the workers had been warned that the giant ship was about to hit, it’s unclear if they would have had enough time to scramble to safety.

A Brawner representative declined to comment, saying the company is focused on taking care of the families of the workers.