Baltimore Bridge Video Twitter, Reddit Original

Audio captures show within seconds of impact, authorities jumped to clarify which bridge Francis Scott was working on cleaning before the collision with a cargo ship in Baltimore.

Workers had warned over radio traffic how a cargo ship was going to approach the bridge, keeping all traffic halted before impact and working to clean the bridge before the impact.

"Need one person facing south, one person north, keep all traffic on the bridge. There's a ship coming that has lost steering so until we get it under control, we've got all traffic stopped," the individual said.

On the audio, units informed that the bridge had collapsed nearly 90 seconds later. CNN confirmed the bridge collapsed at 1:27 am ET.

"The whole span of it just collapsed. Start, get it started...everyone. The whole span has just collapsed," a person can be heard on the radio.

"Do we know if traffic was stopped?" another person later said.

"I can't go the other way, sir. The bridge has come down," another responded.

Helpers in bridge construction have said that after the collapse, they "feel helpless."

Jim Zimmerman was a welder who assisted in the construction of the Francis Scott Key Bridge in Baltimore in the 1970s. After news of the accident broke, his wife woke him up this morning to start the news.

Zimmerman told CNN Tuesday morning over the phone, "I was just shocked, I never thought that bridge would ever come down."

Watching footage, he said that because of dolphins, and concrete bumpers around the pilings for protection, the ship didn't hit the right place and didn't work the right way. He speculated that the ship either bumped the bumpers or just side-swiped them.

He said, unfortunately, the ship hit the most vulnerable part of the bridge.

"It seems it hit the one place that could bring the whole thing down, where it could hit to take the whole thing down," he said. "It hit probably the most vulnerable part of the bridge."

Zimmerman, now 83, worked on the bridge for two years as a local ironworker in the 1970s.

On Tuesday, workers are conducting search and rescue operations after a cargo ship collided with the Francis Scott Key Bridge in Baltimore, causing it to collapse. According to Maryland Transportation Secretary Paul Wiedefeld, at the time of the bridge collapse, there were at least eight people on the bridge, and at least six of them are still unaccounted for.

CNN meteorologist Derek Van Dam said, however, the flow of water in the Patapsco River and weather conditions could complicate search and rescue efforts.

One contributing factor is how the water is flowing. The water from the Patapsco River will flow out into Baltimore Harbor when the tide comes in Tuesday afternoon. Then, during high tide, there will be a reversal, and the water will flow back into the harbor. Van Dam said this means more challenging conditions for search and rescue boats.

Another contributing factor is the temperature of the cold water, which could be hazardous to anyone in the water. At this moment, the water in the Patapsco River is about 40-50 degrees. The capacity for people to survive in this temperature of water ranges from one to three hours.

Biden said he wants the federal government to foot the entire bill for rebuilding the collapsed bridge. "My objective is to have the federal government pay for the entire reconstruction of that bridge," he said. "I hope Congress will support my efforts - it will take some time."

When asked by a reporter whether the shipping company, which owned the container ship that collided with the bridge, should foot the bill for rebuilding the bridge, Biden said, "We're not waiting for that to happen."

"I've directed my team to work hand in glove with the state of Maryland to get the port back up and to rebuild that bridge as quickly as possible," he added, saying the federal government would work "hand in glove" with the state of Maryland.