What We Know About the Francis Scott Key Bridge Collapse in Baltimore

The main shipping channel into the Port of Baltimore fully reopened on Monday, about 11 weeks after a giant cargo vessel struck the Francis Scott Key Bridge, toppling the bridge into the channel and killing six construction workers.

The move followed nearly two months of efforts to disentangle the ship, the Dali, from the wreckage of the bridge and move it away from the site of the accident.

Much still remains unknown about the cause of the ship’s problems.

But federal investigators did offer some new insights in May, saying in a preliminary report that the ship had suffered two electrical blackouts in the hours before it left the port on March 26.

And a U.S. Coast Guard leader pointed to a continuing vulnerability in the nation’s infrastructure, telling a congressional committee that bridges around the country needed to be assessed, because the much larger ships now navigating U.S. ports have raised the risk of deadly collisions.

Here’s what we know about catastrophe, the nation’s deadliest bridge collapse in more than a decade.

Why did the ship hit the bridge?

A National Transportation Safety Board report released on May 14 indicated that the 947-foot-long cargo vessel, the Dali, had been suffering power problems before it left the Port of Baltimore, and experienced at least two electrical failures on the day before the accident. Those failures led the crew to adjust the configuration of the electrical system about 10 hours before setting out.