BALTIMORE — The cargo ship that lost power and crashed into a bridge in Baltimore underwent “routine engine maintenance” in the port beforehand, the U.S. Coast Guard said Wednesday, as divers recovered the bodies of two of six workers who plunged into the water. The others were presumed dead, and officials said search efforts had been exhausted.

Investigators began collecting evidence from the cargo ship that struck the Francis Scott Key Bridge. The bodies of the two men, ages 35 and 26, were located by divers in the morning inside a red pickup submerged in about 25 feet of water near the bridge’s middle span, Col. Roland L. Butler Jr., superintendent of Maryland State Police, announced at an evening news conference.

The victims were from Mexico, Guatemala, Honduras and El Salvador, Butler said.

All search efforts have been exhausted, and based on sonar scans, authorities “firmly” believe the other vehicles with victims inside are encased in superstructures and concrete from the collapsed bridge, Butler said.

A coworker of the people missing said yesterday that he was told the workers were on break and sitting in their trucks parked on the bridge when it crumpled.

U.S. Coast Guard Rear Admiral Shannon Gilreath said at a news conference that authorities had been informed that the ship was going to undergo the maintenance. He added that they were not informed of any problems.

The ship collided into a support pillar early Tuesday, causing the span to collapse. The bodies of two of six workers who plunged into the water were recovered earlier Wednesday.

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.”