A preliminary report from the National Transportation Safety Board (NTSB) found that two power outages before the accident disabled equipment and that the vessel lost power twice in the 10 hours leading up to the crash.
In the aftermath, NTSB investigators were tasked with finding out what happened. They eventually discovered a loose cable, which they believe may have tripped two breakers, causing a power surge that knocked out electricity.
A second power outage occurred while the crew struggled to restart the engine. This is most likely the result of the pump supplying fuel to the generator stopping and not restarting automatically.
Erratic generators may have caused additional power fluctuations that tripped the ship’s breakers. This is a common phenomenon faced by sailors, but it mostly happens at sea.
Sal Mercogliano, a maritime historian and former merchant mariner, said the silence the sailors must have heard at that moment was “the worst sound I have ever heard” on the ship.
“At that moment you realize you no longer have control of the ship,” he added. “It’s a nightmare… The time to restore power is very short.”
In Dali’s case, it was already too late. It was later revealed that it took about four minutes for the ship to lose power and hit the bridge.
Despite the destruction and loss of life, officials are relieved that the incident did not become more serious.
On the night of the collapse, police were able to stop traffic, with the last vehicle passing over the bridge just 40 seconds before it collapsed.
“Cars would have continued to come in,” Maryland Gov. Wes Moore said. “By the time people driving the vehicles realized the bridge was gone, it would have been too late.”
“Words cannot express how many lives they have saved,” he added. “Because there are countless answers.”
