We've been speaking to locals about the impact of this bridge collapse.

Retired structural iron worker Priscilla Thompson became emotional as she described the "horrendous crash" early this morning.

"It shook the entire house. It was catastrophic," she told the BBC's Tom Bateman.

"It was a beautiful bridge, so fortified and so straight from every angle, the pride and glory, the bridge of bridges".

"I just made a birthday card for my husband and drew the Key Bridge in it, that's how close that bridge was to me," she added.

"I am devastated".

Bernd Debusmann Jr
Reporting from Dundalk, Maryland

I've just caught my first glimpse of the collapsed bridge, which is probably about a third of a mile from where I'm standing.

From my view point near an emergency staging area, I can see a large portion of the bridge collapsed into the water, with a huge metal chunk tilted to its side.

The ship is still there, motionless at what was perhaps halfway across the bridge. Stacks of multi-coloured shipping containers are still sitting on top of the vessel.

About 50m to my right, emergency crews are milling about, some of them taking pictures while others speak into radios.

Two helicopters are overhead - one flying at a low altitude and the other hovering much higher.

This map shows the route of the container ship that collided with the bridge.

It left the Port of Baltimore at 00:44 local time (04:44 GMT) before straying off course and hitting a column at 01:30.

It was beginning a journey to Sri Lanka at the time of the crash.

Bernd Debusmann Jr
Reporting from Dundalk, Maryland

I've just arrived in Dundalk, Maryland, at a park near the collapsed bridge.

In normal times, one would clearly be able to see the bridge from here, but access is being tightly restricted and many of the roads are cordoned off by emergency crews.

The sun is just rising, but the scale of the response is clearly evident. From where I am standing I can see two helicopters circling the area, including a red Coast Guard helicopter.

A rescue boat also just sped by with its emergency lights on, and there's a trailer from Baltimore County Emergency Management here.

Getting here itself was complicated - on the highway near the bridge, I saw 15 or so tractor trailers parked on the side of the road, presumably waiting to figure out where to go with the bridge collapsed.

Stay with us for more updates from the scene.

We've just been hearing from Baltimore officials, following news that a major bridge in the Maryland city has collapsed. Here's a round-up of what they said:

• Baltimore City Fire Department Chief Wallace said that at around 01:50 local time, the first emergency units arrived to a completely collapsed bridge
• Wallace said it became clear that there were people in the water and two have been rescued so far, one is in a very serious condition
• Mayor of Baltimore Brandon Scott described the incident as an "unthinkable tragedy" and that his office was working with every part of government to "get through this tragedy"
• He added that officials were investigating whether there was a possible oil spill in the river
• The fire chief said "there is absolutely no indication this is terrorism"

Katy Austin
Transport Correspondent

Container shipping expert Lars Jansen describes what’s happened as a “major disaster” which will “create significant problems on the US East Coast for US importers and exporters”.

On top of some 21,000 units of cargo having to go through other ports in the region, he says “multiple merchant vessels are now trapped in the port of Baltimore”. None are container ships but there are some bulk carriers.

Jansen says he cannot remember hearing of an event like this before.

He says it will be a big issue for shipping in the region, leading to some delays and added costs. However from a global perspective, it will not have a significant impact.

Alex Delsordo, owner of the Hard Yacht Cafe located on a marina close to the bridge, says one of his employees, a former first responder himself, heard the collapse.

"He said it sounded like a very large, long rumbling, like a train going through," Delsordo tells the BBC.

First responders - police, fire crews and divers - have been at the cafe since around 03:00 local time to "fuel up" for the operation, he says.

The bridge was a local landmark and provided "the most beautiful views in all of Baltimore", he adds.

Katie Silver
Reporting from Singapore

A Singapore-based shipping expert who has sailed cargo ships through Baltimore’s port many times has been speaking with the BBC.

“The vessel had just departed from berth and made a turn before hitting the bridge”.

Having seen the footage, he has said there were a few possible causes:

1. Main engine failure
2. Steering failure
3. Generator blackout
4. Possibility of pilot/human error

“It’s an unusual turn. Before a ship departs, we are supposed to carry out all the checks on all elements of the vessel before it departs. It’s part of the departure checklist. So, if everything was done, something was obviously overlooked,” he says, speaking on the basis of anonymity.

“These ships are so huge that even if the speed is slow, the momentum would be huge,” he adds.

He questions when the last structural check of the bridge was carried out. “Having a port right next to the bridge with ships going underneath it all the time – it should have been checked often,” he says.

The White House is "closely monitoring" the situation after the Baltimore bridge collapsed, an official statement says.

"Our hearts go out to the families of those who remain missing as a result of this horrific incident," it says.

"The US Coast Guard is conducting search and rescue for those who remain unaccounted for as a result of the bridge collapse."

It adds senior White House officials are "in touch with the governor and mayor to offer any federal assistance they need", saying there is no indication of "any nefarious intent".

Tiffany Wertheimer
Live reporter

It's nearly 07:00 in Baltimore - and the extent of the damage is becoming clearer in the daylight.

Image source, EPA

Image source, EPA

Fire Chief Wallace says there have been reports of the smell of diesel fuel from the incident area, but gives no confirmation that it means there is an oil spill in the river.

"We hope as the sun comes up, we will get a much better picture if we do have a fuel spill and what the impact has been so far," he says.

He says the local environmental department and coastguard are on site.

"There is absolutely no indication this is terrorism," the fire chief says, on the ship crashing into the bridge in Baltimore.

He adds that there is also no indication that this was intentional.

"Our criminal intel is working with the FBI and other federal and state agencies to get all the intel that we have."

Mayor Scott rejects a question on when the bridge might be rebuilt.

"Right now there are people in the water that we have to get out", Scott says.

He goes on to say the scene of the bridge collapse "looked like an action movie".

"Never would you think you would see the key bridge tumble down like this," adding that "our focus should be the preservation of life".

Baltimore Fire Chief James Wallace says they do not have any information as to whether there was a problem with the ship.

He says police have not spoken to the pilot on the vessel yet.

Wallace is now taking questions from the media, and has been asked about the various numbers of casualties we have heard throughout the morning.

Wallace says exact numbers have not yet been nailed down but confirms at least seven people fell into the water, placing emphasis on "at least".

The Baltimore fire chief says: "I can tell you our sonar has detected the presence of vehicles submerged in the water", but adds that he can't confirm how many.

He says the crew are still on board the ship. "We are in communication with the Coast Guard", he adds.

His team have been told that some workers are still on the bridge, but that they are yet to confirm this.

Mayor of Baltimore Brandon Scott says "this is a unthinkable a tragedy".

He says he is thinking of the families affected and thanks first responders.

"We have to be thinking about the families and people impacted, folks who we have to try to find. This is what our focus should be on right now, we're going to continue to work in partnership with every part of government to do everything we can to get us through the other side of this tragedy."

"We are still very much in an active search and rescue posture at this point and we will continue to be for some time," says the fire chief.

"We have a large area that we have to search. This includes on the surface of the water, subsurface, as well as on the deck of the ship itself."

He says they may be looking for upwards of seven individuals.

Officials earlier said there could be as many as 20 people in the water.

Baltimore City Fire Department chief James Wallace says two people were rescued from the water.

"One individual refused service and refuse transport essentially that person was not injured," he says.

"However, there was another individual that's been transported to a local trauma centre that is in a very serious condition."

James Wallace, the Baltimore fire chief, says early this morning, 911 call centre operators got numerous calls indicating several people were in the water of the Patapsco River.

At 01:50 local time, the first unit arrived on scene and reported a complete collapse of the bridge, and it became clear that people had been on the bridge when it collapsed.