The entire Key Bridge is in the harbor.

The Francis Scott Key Bridge plunged into the water overnight after it was hit by a cargo container ship.

I wanted to know what the bang was.

A ship hit the Key Bridge, sinking. The bridge is gone. Holy hell.

Video shows smoke coming from the ship before it hit the bridge.

The bridge is normally a major artery spanning the Patapsco River.

And though the collapse happened in the early morning hours, 1:30 a.m., video shows cars crossing moments before the ship hits.

The traffic then paused, but vehicles were still on the bridge as it then crumbled into the water.

Fire department and Coast Guard teams rushed to the scene, (with) rescuers searching the water overnight.

It's all very much in an active search and rescue posture.

Our sonar has detected the presence of vehicles submerged in the water.

The ship is an almost 950-foot container vessel called Dali, headed from Baltimore to Sri Lanka.

The Synergy Marine Corporation says it collided with the bridge pillar, and all of its crew members, including the two pilots, have been accounted for.

The ship reportedly lost power while in the water.

This morning, with the sun rising, search teams continue looking for any survivors in the water as the Baltimore area reels from a major collapse.

Tom, we know that there were vehicles in the water, as that official pointed out. The weather is very cold, so if there are survivors who are still in the water, how long can they safely remain in those cold temps?

Yeah, 40, 45 degrees in the water; 32 degrees outside right now.

We checked with the University of Minnesota Duluth, and they're saying at about 7 minutes if you're in the water,

you start to have exhaustion, and then you may have — if you're lucky, if you've got a flotation device, if you've got the right gear — you might be able to survive for an hour.

So, we are now several hours, almost 6 hours, into this episode.

Survivability is really potentially very, very challenging.

But overhead helicopters continue to search the water for any signs of survivors.

And this is an all-hands-on-deck effort in terms of Baltimore and Maryland state authorities and surrounding counties, all sending mass resources into this area, trying to find anybody who might be in the water.

Let's talk, Tom, if we could, about this cargo ship itself.

Earlier, you and I were on the air, we could not even make out, in the dark weather, if the ship was still afloat. We now see that it is.

We've been told by authorities that the crew remains on the ship, including presumably the pilot of this vessel.

What is the investigation going to look like?

Now, as I understand it, by law, if you're traveling these very complex waters in and around the Baltimore Harbor and the Chesapeake Bay, you have to have a local marine pilot on (board) because it is so complex.

We can even roll the video, Tom.

In the moments before it hits this structure, this key part of the pylon of the bridge's structure, the ship looks dark.

It looks like it's lost power.

Yes, and there was one report that it had, in fact, lost power.

The fire department chief is saying that they will not put people on board that ship until they do a full damage assessment to determine how safe it is.

And then they've got to evacuate the crew and determine how seaworthy the vessel is.

However, at the moment, it seems to be fine.

The NTSB will actually be running the investigation into how this happened.

But I must say, the locals here are stunned that this ship would first of all crash into one of these pylons.

Again, we don't know if they had control of the ship.

And secondly, stunned that this bridge would be so vulnerable to collapse with the ship hanging a pylon.

Just a whole series of questions that you can imagine the entire city is asking.

I would make the point we are right up against, very close to, I-95, that critical north-south corridor on the East Coast.

I-95 is open; I-695, however, is closed.

so if you are planning to come up and down the East Coast, be aware that the area around Baltimore is going to be really, really trying and problematic just in terms of traffic.

And the Port of Baltimore itself, one of the busiest in the country, is going to be reeling from this and trying to determine how safe it is to move ship traffic in and out.

Live pictures out of Baltimore as the sun's coming up, Tom. The Francis Scott Key Bridge perhaps totally collapsed this morning, a mile-and-a-half thoroughfare right around Baltimore City.