Almost 2 months after it destroyed Baltimore's Key Bridge, the Dali cargo ship has been moved

Explosives are detonated to free the container ship Dali after it was trapped following its collision with the Francis Scott Key Bridge. (Leah Millis / Reuters)

After 55 days stuck in the Patapsco River, the Dali cargo ship was hauled away from the site of its catastrophic crash into the Francis Scott Key Bridge – a crucial step toward fully reopening the busy Port of Baltimore.

Several tugboats started pulling the 106,000-ton vessel at around 7 a.m. Monday, officials said. The ship travelled about 1 mph to the Seagirt Marine Terminal in Baltimore.

Federal authorities are still investigating why the cargo ship lost power, veered off course and smashed into the Key Bridge on March 26 – killing six construction workers.

But the Dali's move from scene of destruction means authorities will soon be able to open more channels to and from the Port of Baltimore – a critical hub for commerce, especially for the sugar and automotive industries nationwide.

"We've been ahead of schedule with getting our channels open," US Coast Guard Lt. Cmdr. Kate Newkirk told CNN affiliate WBAL over the weekend.

"We plan to open a 400-foot by 50-foot channel (Monday) and, hopefully in the next week or so, we'll be at that 700-foot channel, which is our goal."

Maryland Gov. Wes Moore said he expects the main federal channel that had been clogged by wreckage to reopen by the end of this month.

"I'm proud that we're on track," Moore told NBC's "Meet the Press" on Sunday. "By the end of May, we'll have that federal channel reopened."

Authorities probe the cause of the calamity

Multiple investigations are underway to try to determine who might be responsible for the catastrophic crash. Last month, Baltimore Mayor Brandon Scott announced a probe "to hold the wrongdoers responsible and to mitigate the immediate and long-term harm" to residents.

The ship's Singaporean owner, Grace Ocean Private Limited, and manager, Synergy Marine PTE LTD, filed a petition in federal court last month asking for a US$43.6 million limit on potential liability payouts.

The city of Baltimore has asked the court to deny that request.

The FBI, the US Coast Guard and the National Transportation Safety Board are also investigating.

Last week, the NTSB released a preliminary report saying the Dali had a pair of electrical failures minutes before the collision, as well as two blackouts while the ship was in port one day earlier. One of those in-port blackouts was caused by a crew error, the report said.

The FBI and Coast Guard are looking into whether the crew failed to report the in-port power outage, according to a US official familiar with the matter.

The crew has been stuck for nearly 2 months

The Dali's 21-member crew has been confined to the ship since March 26 and will likely have to stay on board "for the foreseeable future," the ship's management company said.

There is no immediate plan for what the 20 Indian and one Sri Lankan crew members will do after the Dali is relocated Monday, said Barbara Shipley, mid-Atlantic labor representative for the International Transport Workers' Federation.

The seamen's one-month visas expired during the nearly two months they've been trapped on board, according to one of the unions representing the crew members.

The seafarers have been without their cell phones for more than a month because the FBI confiscated the devices as part of their ongoing investigation, Shipley said.

"It's important to get these gentlemen back home to their families," she said.

But international maritime regulations requires the vessel to have some staff on board. Shipley hopes officials will prioritize deciding which of the men can go home and which need to stay behind.

Though the seafarers have been stuck on board, they have not remained idle. They've played a critical role in maintaining the ship's functioning and helping salvage crews navigate the boat, said Darrell Wilson, spokesperson for Synergy Marine Group – the company that manages the Dali vessel.

Synergy has provided mental health services for the seamen, who have been grappling with the deaths of the six construction workers killed in the crash.

"It has been tough for the seafarers, primarily (because) they know that there's been loss of life," said Gwee Guo Duan, assistant general secretary of the Singapore Maritime Officers' Union – one of the unions representing crew members on the Singaporean-flagged ship.

"It is tough for them, being on board and having to look at the accident site every single day."

CNN's Zoe Sottile, Chris Boyette, Nicole Grether, Gloria Pazmino and Jillian Sykes contributed to this report.