NTSB Issues Investigative Update for Baltimore Bridge Collapse

​​​WASHINGTON (June 24, 2024) — The National Transportation Safety Board published an investigative update Monday for its ongoing investigation of the March 26 contact of containership Dali with the Francis Scott Key Bridge and subsequent bridge collapse.

The investigative update does not contain analysis and does not discuss probable cause in this ongoing investigation. As such, no conclusions regarding the cause of the contact should be made based on the information contained in the update. The information in the update is preliminary and subject to change as the investigation continues.

During the accident voyage, as described in the NTSB preliminary report,​ electrical breakers HR1 and LR1 unexpectedly opened when the vessel was three ship lengths from the Francis Scott Key Bridge, causing the first blackout to all shipboard lighting and most equipment. While examining and testing the vessel’s electrical power distribution system and control circuitry, NTSB investigators noted an interruption in the control circuit for HR1’s undervoltage release. 

NTSB investigators continue to examine components at the NTSB Materials Laboratory. Investigators will continue to evaluate the design and operation of the vessel’s electrical power distribution system, and investigate all aspects of the accident to determine the probable cause and identify potential safety recommendations. 

The Dali was transiting out of Baltimore Harbor when it lost electrical power and propulsion and struck the southern pier supporting the central truss spans of the Francis Scott Key Bridge. A portion of the bridge subsequently collapsed. Six construction crewmembers on the bridge at the time of the contact were fatally injured, one construction crewmember was seriously injured and one crewmember on the Dali was injured. 

Read the investigative update online​.