The main shipping channel near the site where the Francis Scott Key Bridge collapsed should be restored by the second week of June, the U.S. Army Corps of Engineers said Friday.

The Corps said returning the federal channel in the Patapsco River to its 700-foot width and 50-foot depth has been a complicated process and the target dates could move. About one-third of the bridge’s truss is still visible above the water and parts are still buried in the mud.

“This effort is more complex than initially estimated,” Col. Estee S. Pinchasin, the Corps’ Baltimore District commander said in a statement. “Salvage crews must dig out the bottom cord of this truss to access the areas needing to be cut.”

Refloating and removing the Dali on May 20 allowed expansion of a limited access channel to the Port of Baltimore to 400 feet wide and 50 feet deep, the Corps said. That opened the river to deep-draft commercial vessels.

“We are proud of the unified efforts that have partially reopened the Federal Channel to port operations,” said Lt. Gen. Scott Spellmon, commanding general of USACE.

There’s still wreckage on the riverbed, with salvage crews cutting into three sections some of the remaining parts stuck on the riverbed, Pinchasin said. The target dates for completing the work to restore the federal channel are between June 8-10.

“We are not taking our foot off the gas,” Pinchasin said.

The Dali struck the Key Bridge in the early morning hours of March 26, causing the span to cascade into the water and temporarily shutting off access to the Port of Baltimore. Six construction workers were killed in the collapse.

The FBI is conducting a criminal investigation into what caused the wreck and collapse.