NTSB Timeline Reveals Crucial Minutes Leading Up to Baltimore Bridge Strike

A timeline of events released by the National Transportation Safety Board (NTSB) has revealed the Maryland Transportation Authority (MTDA) dispatchers had less than three minutes warning that the MV DALI was having trouble as it departed the Port of Baltimore early Tuesday morning.

Moreover, dispatchers were told of the threat to the Francis Scott Key Bridge about a minute and half before the 984-foot containership, loaded with 4,679 twenty-foot equivalent containers, struck one of the bridge’s pillars, causing it to collapse. On board the ship were its 21 crew members and two local pilots.

In those crucial minutes, MDTA dispatchers were able to warn two patrol units located on either end of the bridge to close the bridge to vehicle traffic, an action that likely saved lives. Tragically, six workers on the bridge at the time of the collapse are presumed dead.

The timeline provides a harrowing account of just how quickly the situation unfolded.

Full Coverage: Baltimore Bridge Collapse

The NTSB released the timeline after boarding the ship on Wednesday to gather perishable, factual evidence. The agency also revealed 56 containers with hazardous materials, some of which were breached.

The U.S. Coast Guard recovered approximately 6 hours of voyage data recorder (VDR) data from the DALI on the morning of the accident and provided it to the NTSB. The data covers the period from 00:00 to 06:00 EDT on March 26, 2024. The NTSB is continuing to obtain the remaining 30 days of data that the VDR is required to record.

The VDR data, which includes audio from the ship’s bridge and VHF radios, varies in quality due to background noise and alarms. Further analysis will be conducted at the NTSB’s lab to enhance the audio clarity. All information is preliminary and subject to final validation and change.

The VDR also recorded limited system data such as ship speed, engine RPM, rudder angle, ship heading, and some alarm information.

The times expressed below are as recorded by the VDR and converted to local eastern daylight time, as shared by the NTSB:

The VDR recorded the ship’s departure from Seagirt Marine Terminal at approximately 00:39 EDT, recorded the ship’s transit outbound in the Fort McHenry Channel, and the striking of the Francis Scott Key Bridge (1-695).

By 01:07 EDT, the ship entered the Fort McHenry Channel.

By 01:24 EDT, the ship was underway on a true heading of approximately 141 degrees in the Fort McHenry Channel at an indicated speed over ground of approximately 8 knots/9 miles per hour.

At 01:24:59 EDT numerous aural alarms were recorded on the ship’s bridge audio. Around the same time, VDR ship system data ceased recording, however, the VDR audio continued to be recorded using the VDR’s redundant power source.

Around 01:26:02, the VDR resumed recording ship system data. During this time, there were steering commands and rudder orders on the VDR audio.

Around 01:26:39 the ship’s pilot made a general VHF radio call for tugs in the vicinity of the DALI. MDTA data from around this time indicated the pilot association dispatcher phoned the MDTA duty officer regarding the blackout.

Around 1:27:04, the pilot commanded the DALI to drop the port anchor and issued additional steering commands.

Around 1:27:25, the pilot issued a radio call over the VHF radio and reported the DALI had lost all power approaching the Key Bridge. Around this time, MDTA data shows the following occurred:

• MDTA duty officer radios two units already, one on each side of the bridge, to close the bridge.

• All lanes are shut down by MDTA.

Below is the released radio audio of the dispatch to the two patrol units [NOT INCLUDED IN THE NTSB TIMELINE]:

NTSB timeline continues:

Around 1:29:00, the ship’s speed over ground was recorded as just under 7 knots/8 miles per hour. From this moment until approximately 1:29:33, VR audio recorded sounds consistent with the collision with the Key bridge. Additionally, around this time, an MDTA dash camera shows the bridge lights extinguishing. Additional analysis of the VR audio and comparison of other time sources will be needed to determine the exact time of contact between the DALI and Key Bridge.

At 1:29:39 the pilot reported the Key Bridge down over VHF to the USCG.

NTSB engineers will continue working to identify and validate this data. The NTSB will also convene a group of technical experts at a later date to review the entire recording and develop a detailed transcript of the dialogue and events recorded.