BALTIMORE >> Investigators began collecting evidence today from the cargo ship that plowed into Baltimore’s Francis Scott Key Bridge and caused its collapse, while in the waters below divers searched through twisted metal for six construction workers who plunged into the harbor and were feared dead.

The investigation picked up speed as the Baltimore region reeled from the sudden loss of a major transportation link that’s part of the highway loop around the city. The disaster also closed the port that is vital to the city’s shipping industry.

Officials with the National Transportation Safety Board boarded the ship and planned to recover information from its electronics and paperwork, NTSB Chair Jennifer Homendy said.

The agency also is reviewing the voyage data recorder recovered by the Coast Guard and building a timeline of what led to the crash, which federal and state officials have said appeared to be an accident.

The ship’s crew issued a mayday call early Tuesday, saying they had lost power and the vessel’s steering system just minutes before striking one of the bridge’s columns.

At least eight people went into the water. Two were rescued, but the other six — part of a construction crew that had been filling potholes on the bridge — were missing and presumed dead.

The debris complicated the search, according to a Homeland Security memo described to The Associated Press by a law enforcement official. The official was not authorized to discuss details of the document or the investigation and spoke to AP on condition of anonymity.

Maryland Gov. Wes Moore said the divers faced dangerous conditions.

“They are down there in darkness where they can literally see about a foot in front of them. They are trying to navigate mangled metal, and they’re also in a place it is now presumed that people have lost their lives,” he said today.

Among the missing were people from Guatemala, Honduras and Mexico, according to diplomats from those countries. Three Mexicans were on the bridge. One was rescued, and two are missing, said Mexico President Andrés Manuel López Obrador.

Capt. Michael Burns Jr. of the Maritime Center for Responsible Energy said bringing a ship into or out of ports with limited room to maneuver is “one of the most technically challenging and demanding things that we do.”

There are “few things that are scarier than a loss of power in restricted waters,” he said. And when a ship loses propulsion and steering, “then it’s really at the mercy of the wind and the current.”

Video showed the ship moving at what Maryland’s governor said was about 9 mph (15 kph) toward the 1.6-mile (2.6-kilometer) bridge. Traffic was still moving across the span, and some vehicles appeared to escape with only seconds to spare. The crash caused the span to break and fall into the water within seconds.

The last-minute warning from the ship allowed police just enough time to stop traffic on the interstate highway. One officer parked sideways across the lanes and planned to drive onto the bridge to alert a construction crew once another officer arrived. But he did not get the chance as the powerless vessel barrelled into the bridge.

Attention also turned toward the container ship Dali and its past.

Synergy Marine Group, which manages the ship, said the impact happened while it was under the control of one or more pilots, who are local specialists who help guide vessels safely in and out of ports.

The ship, which was headed from Baltimore to Sri Lanka, is owned by Grace Ocean Private Ltd., and Danish shipping giant Maersk said it had chartered the vessel.

The vessel passed foreign port state inspections in June and September 2023. In the June 2023 inspection, a faulty monitor gauge for fuel pressure was rectified before the vessel departed the port, Singapore’s port authority said in a statement today.

The ship was traveling under a Singapore flag, and officials there said they will be conducting their own investigation in addition to supporting U.S. authorities.

The sudden loss of a major transportation link that loops around the city and carries 30,000 vehicles a day, and the disruption of a vital shipping port, will affect not only thousands of dockworkers and commuters but also U.S. consumers who are likely to feel the impact of shipping delays.

The Port of Baltimore is a busy entry point along the East Coast for new vehicles made in Germany, Mexico, Japan and the United Kingdom, along with coal and farm equipment.

Ship traffic entering and leaving the port has been suspended indefinitely.

Transportation Secretary Pete Buttigieg has said it was too soon to give a time frame for clearing the channel, which is about 50 feet (15 meters) deep. President Joe Biden said he expects the federal government to pay the entire cost of rebuilding the bridge.

From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collisions, according to the World Association for Waterborne Transport Infrastructure.