There are photos that show the port anchor was dropped. Here's one:
https://gcaptain.com/ship-lost-control-before-hitting-baltimore-bridge/
Ship Lost Control Before Hitting Baltimore Bridge
John Konrad
The Francis Scott Key Bridge in Baltimore collapsed early today after the large containerships Dali struck a primary support column. Two individuals were rescued, one is seriously injured, and authorities estimate that seven people are currently missing, though the number could be higher. This incident represents the most severe US bridge collision since the Tampa Skyway Bridge disaster in 1980. The event occurred in the early morning hours as the ship was leaving the port under pilotage.
Agencies are reporting the containership Dali, which collided with a Baltimore bridge on Tuesday, “lost propulsion” while exiting the port. The crew on board alerted Maryland officials that they had lost control of the vessel, as reported by ABC News, citing an unclassified U.S. intelligence report.
“The vessel notified the MD Department of Transportation (MDOT) that they had lost control and a collision with the bridge was possible,” ABC quoted the Cybersecurity and Infrastructure Security Agency’s report as saying. “The vessel struck the bridge, causing a complete collapse.”
According to Marine Traffic the ship departed the Seagirt Marine Terminal in the Port of Baltimore at approximately 00:30 local time, sailed northwest past the Nuclear Ship Savanah then turned southeast to depart the harbor, released the tugboats, and collided with the bridge at approximately 01:38.
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