(NewsNation) — Investigators have released footage providing a look inside the cargo ship that struck and caused the collapse of the Francis Scott Key Bridge in Baltimore last week.

The video, filmed Mar. 28 by the National Transportation Safety Board, shows NTSB personnel inspecting damage aboard the Dali, the 984-foot container vessel that collided with the bridge on Mar. 24.

The huge vessel was carrying nearly 4,700 shipping containers, 56 of them with hazardous materials inside. Fourteen were destroyed, officials said. Industrial hygienists who evaluated the contents identified them as perfumes and soaps, the Key Bridge Joint Information Center said, and there was “no immediate threat to the environment.”

Six construction workers who were on the bridge are presumed dead. The drivers of more than 30,000 vehicles that crossed the bridge daily must find a new route around or over the Patapsco River. And shipments at the Port of Baltimore will be shut down for some time, forcing numerous businesses to find alternative means of getting their goods in and out of the U.S.

Divers had already recovered the bodies of two men from a pickup truck in the Patapsco River, but the nature and placement of the debris has complicated efforts to find the four workers still missing and presumed dead.

Maryland’s governor credited first responders, who “moved heroically” after only 90 seconds separated the first Mayday call from and when the cargo ship Dali struck the bridge, causing the structure to collapse, sending workers into the frigid waters below.

One of the two people who survived the collapse of the Francis Scott Key Bridge this week “literally saw” the structure collapse as it plunged into the Patapsco River, Maryland Gov. Wes Moore said Wednesday.

Officials announced that survivors include a Mexican national, who was part of a construction crew working on the bridge, and a Maryland state inspector who was overseeing work on the bridge when a cargo ship struck the bridge early Tuesday morning. Neither of the survivors has been publicly identified.

Officials said the tragedy could have been far more disastrous had it not been for the quick actions of the first responders. Emergency workers had less than two minutes to not only prevent traffic from entering the bridge but also had to get out of their vehicles and audibly warn construction workers to get off the structure, officials said.

Rebuilding Baltimore’s collapsed Francis Scott Key Bridge could take anywhere from 18 months to several years, experts say, while the cost could be at least $400 million — or more than twice that.

The Associated Press contributed to this report.