BALTIMORE — Investigators began collecting evidence Wednesday 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 was 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 Wednesday.

Among the missing were people from Guatemala, Honduras and Mexico, according to diplomats from those countries.

One worker, a 38-year-old man from Honduras who came to the U.S. nearly two decades ago, was described by his brother as entrepreneurial and hard-working. He started last fall with the company that was performing maintenance on the bridge.

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 toward the 1.6-mile (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 the vessel barreled into the bridge.

Attention also turned to 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 Wednesday.