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

Investigators on Wednesday began collecting evidence from the vessel that struck the Francis Scott Key Bridge in the previous day. The bodies of the two men were located in the morning inside a red pickup submerged in about 25 feet (7.6 meters) of water near the bridge’s middle span, Col. Roland L. Butler Jr., superintendent of Maryland State Police, announced at an evening news conference.

He identified the men as Alejandro Hernandez Fuentes, 35, who was from Mexico and living in Baltimore, and Dorlian Ronial Castillo Cabrera, 26, who was from Guatemala and living in Dundalk, Maryland.

The victims, who were part of a construction crew fixing potholes on the bridge, were from Mexico, Guatemala, Honduras and El Salvador, Butler said.

Maryland Gov. Wes Moore addressed their families in Spanish during the news conference, saying, “Estamos contigo, ahora y siempre,” which means, “we are with you, now and always.”

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. Divers are to return to search for remains once the waters are clear of debris.

Jesus Campos, who has worked on the bridge and knows members of the crew who died, said on Tuesday that he was told they were on a break and some were sitting in their trucks parked on the bridge to warm up when the it collapsed.

U.S. Coast Guard Rear Admiral Shannon Gilreath said at the news conference that authorities had been informed that the ship was going to undergo the maintenance.

“As far as the engine goes, we were not informed of any problems with the vessel,” he said. “We were informed that they were going to conduct routine engine maintenance on it while it was in port. And that’s the only thing we were informed about the vessel in that regard.”

The investigation ramped up 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 to recover information from its electronics and paperwork and to do interviews with the captain and other crew members, NTSB Chair Jennifer Homendy said during a news conference. Twenty-three people, including two pilots, were on the ship when it crashed, she said.

The ship was also carrying 56 containers of hazardous materials including corrosives, flammables and lithium ion batteries, Homendy said. She added that some containers were breached and that a sheen on the water from those materials would be handled by authorities.

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 initially went into the water, and two of them were rescued Tuesday, officials said.

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.

Gov. 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,” Moore said Wednesday, adding that they were also trying to navigate mangled metal.

One missing 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 year with the company that was performing maintenance on the bridge.