A comment left on the follow-on video. Speculative, but … he surely knows a whole lot more about this stuff than I do:
Well, if they did drop an anchor while still making headway, that by itself could cause the bow to pull to one side.
Or, if they did put on a large astern bell (try to make the ship go in reverse to slow the ship down), that too could have caused the bow to swing (astern bells make the rudder less effective, as some have speculated may have helped doom RMS Titanic).
Or, they might have been intending to go straight but, not unlike how you will often make slight adjustments at the wheel of your car even while going down a straight road, the helmsman was making a minor correction just as the ship lost power (and perhaps steering control as well—imagine what would happen if, in addition to your car engine stopping, your steering wheel froze just as you were making a slight adjustment to get back towards the center of your lane: you’d keep drifting that way as you coasted to a stop, keeping in mind ships can’t brake like a car can).
Or… who knows. Doubtless there will be an investigation.
ETA: If it is in fact a single propeller ship, then there is also a thing called “prop walk” that comes into play.
You need to use the rudder to counteract prop walk on a single screw ship. (But, again, even on a twin screw ship with counter-rotating propellers, you will need to make fine adjustments of the rudder to keep going straight, even on a perfect calm).
In this case, the active construction probably made that happen. I’m guessing there were lane restrictions & cones & blocking vehicles already up there. Given word, it would be fairly easy for one vehicle to pull out & block the one remaining lane of open traffic shutting down anyone else from driving over
It’s also an interstate bridge - sidebar rant - whenever I’ve seen construx on an interstate, across multiple states, there’s a state trooper sitting in the mix; not sure what they’re doing there; it’s not like I’m going to fly along when I see all of the yellow lights but suddenly slow down for one red & blue vehicle parked behind the cones. Also the construction vehicles are better for the drivers to hit because of the scorpion barriers they have rather than hitting the back of a cop car that doesn’t have that absorption protection. /rant
There was most likely a cop sitting in his car just sitting there not doing much. It would have been easy for him to put it in gear & turn into traffic blocking the road; especially if traffic was light at that time of night.
This helps! 
Note that, after the 2007 Minneapolis collapse, “recovery of deceased victims took over three weeks” – and that was considered a smooth-running operation.
I was in the surface Navy. In home port we often had nuclear subs berthed nearby and it was evident that they got very special care (which we never begrudged them).
This was the first time I’ve had an opportunity to see a video. I didn’t see at what point it happened, but sometime before the moment of impact the only vehicles on the bridge that I could see were the construction vehicles. I’ll have to look again when I have the chance.
That’s what I saw as well. A couple of cars going right to left presumably made it off just in time – unless they were still on a final segment of the bridge when it went down.
I’m a night photographer & I shoot a lot of bridges so I have experience in this area. You wouldn’t necessarily see cars on the bridge. Remember, what you are seeing is work trucks (higher than cars) with lightbars on their roof, that are designed to illuminate in all directions. In the video, you can see one of the work trucks lights reflecting on the water as it blinks on/off, that’s because it’s pointing towards the direction of the camera. The majority of a car’s lights are going only forward or rearward, not so much light out to the side; IOW, they’re not so bright. Also, look at this image from Google maps, The red car’s lights are below the level of the Jersey barriers; you wouldn’t see any lighting from this vehicle or a similar one in the video that was shown.
I have seen some but all of the news reports, one question I haven’t seen asked is about the condition of the cargo ship. I know it has sunk, but is it sinking (albeit slowly). Has the structure integrity been compromise. Were there any injuries on the ship? How big is the crew on a cargo ship?
Yes, I was surprised to learn that my grandmother’s port of entry to the U.S. when she emigrated was Baltimore (my grandfather came later and went through Ellis Island).
Regarding the Cargo ship, it should say "I know it has NOT sunk, but is it sinking?
Is that red car in that image a centipede?
All continuous truss bridges have the tendency that a failure of a single span will likely cause failures of other spans.
This design makes the bridge very resilient to heavy loads on top of the bridge (which is the traditionally agreed-upon way of using bridges), however it’s vulnerable to unexpected loads from the side and beneath, which is what happened here.
I realize that there’s a lot more than economic costs, but this does a good job of revisiting what the largest marine disasters have been from that standpoint.
I was skeptical about Biden’s plan for the USA to pay for replacement so am glad to read insurance details. The billing for the bridge would otherwise come from me as part of the national debt in the worst case. It can’t imagine the invoices and work orders for building a huge bridge.
The bridge was constructed between 1972-77. 5 years. I imagine urgency to reopen the port will see the replacement go up quicker.
There is greater urgency opening up the port than there is to rebuilding the bridge.
I predict a cable-stayed bridge with a main span long enough to get the support piers further from the shipping channel, preferably in shallow water where a large ship will ground itself before hitting the pier. They go up relatively quickly, can have very long main spans, plus are visually appealing. One could be built with minimal impact on shipping traffic.
The Baltimore Harbor Tunnel was a primary access route before they built the Key bridge. My family drove through the tunnel several times on trips. The traffic was bad even in 1968.
The tunnel will really be grid locked now. Thankfully there are alternate bridges.