Good morning, Chairman Graves, Ranking Member Larsen, and Members of the Committee. With me today is our lead investigator on this accident, Marcel Muise; our Acting Director of Marine Safety, Eric Stolzenberg; and other dedicated NTSB staff.

Thank you for the opportunity to be here today to discuss our ongoing investigation into the collapse of the Francis Scott Key Bridge.

On behalf of the NTSB, I want to offer our heartfelt condolences to the families of all those who were lost in this tragedy and our deepest sympathies to those who were injured or otherwise impacted by this event.

I also want to thank our numerous federal and state partners for their support on-scene and throughout this investigation.

Yesterday, we released our preliminary report, which shows that the Dali experienced four total power outages: two on March 25 in port while the ship was undergoing routine maintenance, and two on March 26 during the accident voyage.

Preliminary information indicates that the March 25 blackouts were mechanically distinct from those that occurred on March 26. Two were related to routine maintenance in port; two were sudden and unexpected tripping of circuit breakers on the accident voyage.

On the 25th, a blackout occurred when a crewmember mistakenly closed an engine damper while he was working on the exhaust system. This effectively blocked the engine’s exhaust gases from traveling out of the vessel’s stack, causing the engine to stall.

Vessel power was briefly restored. But insufficient fuel pressure to the online generator caused its speed to decrease. Its breaker opened, and a second blackout occurred.

While recovering from this second blackout, the crew switched to a different transformer and set of breakers from those that had been in use for several months.

Switching breakers is not unusual but may have affected operations the next day; the configuration of the breakers remains under investigation.

On the 26th, when the ship was about 0.6 miles from the Key bridge, one high-voltage and one low-voltage breaker that were powering most of the vessel’s equipment and lighting unexpectedly tripped. As a result, the vessel lost main propulsion.

Bridge equipment also lost power and the voyage data recorder lost system feeds. Bridge audio continued to be recorded.

The crew was able to briefly restore power to the vessel, but another blackout occurred when a different breaker tripped. At this point, the ship was about 0.2 miles from the Key bridge. The crew regained electrical power right before the Dali’s starboard bow struck Pier 17, but they were unable to restore propulsion.

The ship had an emergency generator, which automatically started following the first blackout on the 26th. However, this generator only powers systems like emergency lighting, navigation, radio equipment, alarms, and a steering pump that allowed for low-speed rudder movements — it does not power propulsion. Without the propeller turning, the rudder was less effective; they were essentially drifting. We’re still investigating the exact time the emergency generator started.

Going forward, this is a complex investigation. Our investigators have been on-scene consistently since this accident. In fact, they are on board the vessel as I testify today.

We will continue evaluating the design and operation of the Dali’s power distribution system, including its breakers.

Examination of damage to the vessel will continue when the ship is clear of debris and moved to a shoreside facility.

We’re also working with Maryland as they assess pier protection on their other bridges.

And we’re examining pier protection improvements that have been made following other bridge collapses resulting from marine vessel strikes that we investigated, including the Sunshine Skyway Bridge in Florida; the Queen Elizabeth Causeway Bridge in Texas; and the I-40 Bridge in Oklahoma.

Lastly, there are a lot of questions regarding the fuel. Our investigators found that the ship was running on low-sulfur marine gas oil at the time of the accident, which it had been using since March 21st.

We directed an independent lab to test all fuel stored on the ship, including the fuel that was being burned at the time of the accident. The test results did not identify any concerns related to the quality of the fuel.

Thank you again for the opportunity to testify, and I look forward to your questions.      ​