Operation marks significant step in recovery efforts at the Port of Baltimore, one of the busiest ports in the US.

Live television images of the operation on Monday morning showed a flotilla of tugboats pushing and towing the MV Dali away from the remains of the shattered Francis Scott Key Bridge and towards a marine terminal.

The bridge in the eastern state of Maryland was visible for the first time without the cargo ship, the US Army Corps of Engineers said in a post on social media.

The Key Bridge Response Unified Command said the complex operation would take about 21 hours and involve the coastguard, Army Corps of Engineers, Maryland Department of the Environment and other agencies.

The #FSKBridge site is visible for the first time without the vessel. pic.twitter.com/I8cq2stNsz

— USACE Baltimore (@USACEBaltimore) May 20, 2024

The vessel’s removal marks a significant step in the Port of Baltimore’s recovery after the March 26 collision brought down the bridge.

Six road workers were killed in the collapse, and traffic through the busiest port for car shipments in the US was hindered. The Singapore-flagged ship has been blocking the port since the crash.

On Monday, the extensive damage to the ship’s bow included a large hole above the waterline on its starboard side.

Officials said the Dali would move at about 1.6km per hour (1 mile per hour) on the roughly 4km (2.5-mile) trip back to port, a fraction of the speed it was travelling when it lost power and brought down the bridge.

It will spend several weeks getting temporary repairs at the same marine terminal it occupied before beginning its ill-fated voyage and then move to a shipyard for more substantial repairs.

To refloat the Dali, crews released anchors and pumped out more than 3.7 million litres (more than 1 million gallons) of water that had kept the ship grounded and stable during the complicated cleanup.

Crews conducted a controlled demolition on May 13 to break down the largest remaining span of the collapsed bridge, which was draped across the Dali’s bow. Dive teams then confirmed the path was clear.

Federal investigators said in a preliminary report last week that the Dali had lost electrical power several times before crashing into the bridge as it was leaving the port.

Maryland state officials estimate it will cost $1.7bn to $1.9bn to rebuild the bridge, and they expect its completion by fall 2028.