Horror and heartbreak in Maryland. After that massive cargo ship destroyed the city's largest bridge, six people are presumed dead as one of the nation's busiest ports, which handled $80 billion worth of cargo last year, is essentially shut down until further notice. Abc's Lindsay Davis is at the scene of the catastrophic collapse. Lindsay, what can you tell us? Juju, it's difficult to tell right now, but what is just over my shoulder here is the harbor behind me where the Key Bridge came down last night around 1:30 AM. After receiving a desperate mayday call, police closed off traffic just minutes before the collapse and warned people working on the bridge that the ship was careening toward it, but it was not enough time for some. Tonight, six workers who were filling potholes when the cargo ship hit are still missing. The Coast Guard now says the search and rescue efforts have been suspended. The Port of Baltimore is the ninth busiest in the country, now closed indefinitely as twisted debris and wreckage remain tangled both above and below the water, Juju. Lindsay, thank you. It's hard to overstate just how enormous that ship is. It weighs 95,000 tons, and is roughly as long as the Eiffel Tower is tall.

There are many more questions than answers about how that mammoth ship lost control and caused the devastating collapse. This video captures the moment a typical night on the Baltimore Harbor turns tragic. The whole bridge just fell down. Start as whoever, everybody. The whole bridge just collapsed. A huge stretch of the Francis Scott Key Bridge collapsing after a 95,000 ton cargo ship barreled into a supporting pillar at 1:30 in the morning, Tuesday, just hours before the morning rush hour. We advise the entire bridge, the entire Key Bridge in the Harbor. I advise to hold all traffic from committing to the bridge. Vehicles, including this big rig, still crossing the bridge just moments before impact. As the massive ship collides an entire section of the bridge, breaking apart, crumbling onto the bow of the freighter and into the frigid waters below. Is there a crew working on the bridge right now. The catastrophe, setting off a desperate search and rescue effort for survivors, including a construction team repairing potholes overnight. There are eight individuals. Six are being searched for right now. One was taken to the hospital. Maryland Governor Westmore declaring states of emergency. To hear the words that the Key Bridge has collapsed, it's shocking.

For every single one of us who are Marylanders, the words that the Key Bridge is gone, it still shakes us. Two people were rescued. One admitted to Baltimore's shock trauma center in critical condition. At least six more people remain unaccounted for, all believed to have worked for a company called Brawner Builders. All are believed to have perished. Tonight, the Coast Guard announcing the search efforts have been suspended. At this point, we do not believe that we're going to find any of these individuals still alive. A heartbroken Jesús Campos works for Brawner and says he knows the victims. That was really hard. We are colleagues from work and friends. The Danish shipping company, Maersk, who chartered the dolly, saying to ABC News in a statement, We are horrified by what has happened in Baltimore, and our thoughts are with all of those affected. So far, no injuries or casualties among the ship's crew have been reported. It was about 1:20 in the morning. This ship was taking off on a 27-day journey to Colombo, Sri Lanka. It had about 4,000 containers on board. According to the Department of Homeland Security, the Singaporean motor vessel, DALL-E, lost propulsion as it was leaving the port at the Baltimore Harbor.

A full loss of power and a full breakdown of the system means that the rudder is not responding, whether it's where they're trying to turn the ship with the ship's wheel or if an emergency steering, that you just have no control of the vessel. You really have very little to do at that time. The ship, seen in this video, going completely dark, mere seconds before slamming into that pillar. Then thick black smoke begins billowing into the sky. The power turning off again and then back on. Immediately, the crew puts out a mayday call, alerts the Maryland Department of Transportation and those working at the bridge. Within seconds On the ends of the alert, authorities dispatch police officers to close the bridge to all traffic. I need one of you guys on the south side, one of you guys on the north side, hold all traffic on the key bridge. There's a ship approaching and just lost their steering. So then We got to get that under control. We got to stop all traffic. The officers had only seconds to get the construction crew off that bridge before it collapsed. Just make sure no one's on the bridge right now.

If there's a crew up there, you might want to notify whoever the foreman is, see if we can get them off the bridge temporarily. But it was too late. Yo, what the fuck? What the fuck? One witness capturing the catastrophe and posting it to social media. The ship is massive. The ship hits an immovable object. The ship, in this case, is going to win just due to its mass and its size. Approximately 01:40 hours this morning, our 911 center dispatched a call to the Baltimore City Fire Department. As units were responding, they began to receive numerous calls indicating multiple people in the water. As daylight broke, search and rescue teams combing through the extremely cold waters. Several agencies, including the FBI, led by the United States Coast Guard, looking for survivors via land, air, and sea. President Biden addressing the nation from the White House, pledging support. We're going to send all the federal resources they need as we respond to this emergency. I mean, all the federal resources. We're going to rebuild that port together. This afternoon, Transportation Secretary, Pete Edge Edge dispatched to the site of the collapse, appearing alongside Maryland officials. This is no ordinary bridge.

This is one of the cathedrals of American infrastructure. So the path to normalcy will not be easy. It will not be quick, it will not be inexpensive, but we will rebuild together. With so many unanswered questions, NTSB Chair Jennifer Homende says the search for answers will be painstaking. It is very a cumbersome process. It's a very meticulous process where they have to dig through a lot of information. The National Transportation Safety Board, the NTSB, will be the lead on this investigation, and they will be joined by others on the local and state level, but They will bring in a team of more than 20 people, and that will be everything from structural engineers, bridge engineers, ship experts, to try to figure out exactly what happened here. Abc News has obtained records showing the dolly, built in 2015, had at least two documented issues in the past, as recently as last June for propulsion and auxiliary machinery concerning gages and thermometers. And in 2016, after it was involved in a previous crash in Belgium, inspectors issuing a deficiency for structural conditions concerning a damaged haul imparing seaworthiness. The ship continued sailing after the investigation concluded. Tonight, facing a prolonged port shutdown, the Big Three automakers diverting shipments other ports as companies scramble to reroute cargo.

All traffic from the Atlantic Ocean into the Port of Baltimore now closed off. In Baltimore tonight, Governor Moore expressing deep sympathy to the victim's loved ones. This is a I can't imagine how painful today has been for these families, how painful these hours have been for these families. We will use every asset to make sure they find a sense of closure. And of course, we'll have much more on the collapse on GMA in the morning. Hi, everyone. George Stefanopoulos here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights, and watch live event coverage, click on the right over here to subscribe to our channel. And don't forget to download the ABC News app for breaking news alerts. Thanks for watching.