Four of seven ships trapped in Baltimore Harbor since the Francis Scott Key Bridge collapsed in March have cleared the wreckage and are en route to their destinations.

The Balsa 94, a general cargo ship that sails under Panama’s flag, was first to leave the Port of Baltimore and pass the bridge’s remains, according to Bloomberg ship tracking and the Unified Command Joint Information Center. It was followed by the Saimaagracht cargo vessel, the Carmen vehicle carrier and the Phatra Naree bulk carrier.

Officials in Baltimore established a temporary channel so essential ships can traverse the harbor for the first time since the Singapore-flagged ship Dali collided with the bridge on March 26. The new, 35-foot-deep (11 meters) channel — deeper than previous channels ranging from 11 to 20 feet — will be open between April 25 and April 29, pending inclement weather. Salvage operations are still in progress.  

A safety zone has gone into effect for all navigable waters within a 2,000-yard radius of the Key Bridge, according to Baltimore sub-agent Capes Shipping. Port movements will be suspended for an uncertain amount of time, and “prolonged delays are expected due to the magnitude of the situation,” the group said.

Ships are entering the harbor as well. American Sugar Refining Inc. said a full-size vessel delivered raw sugar from Florida to its Baltimore refinery on April 24 via a new 20-foot channel.