BALTIMORE, March 27 (Reuters) -

Rescuers have lost hope of finding more survivors of the

Baltimore bridge collapse, the coast guard said, as efforts

switched on Wednesday to looking for bodies of the missing and

more answers to why a container ship smashed into the span.

Search divers were expected to return near dawn to the

waters surrounding the twisted ruins of the bridge in Baltimore

Harbor to search for six workers missing and now presumed dead.

The disaster has forced the indefinite closure of the Port

of Baltimore, one of the busiest on the U.S. Eastern Seaboard,

and created a traffic quagmire for Baltimore and the surrounding

region.

As the odds of their survival vanished, the search for the

missing workers was suspended on Tuesday evening, 18 hours after

they were thrown from the fallen Francis Scott Key Bridge into

the frigid waters at the mouth of the Patapsco River.

"We do not believe that we're going to find any of these

individuals alive," Coast Guard Rear Admiral Shannon Gilreath

said at a briefing.

Maryland State Police and U.S. Coast Guard officials said

diminished visibility and increasingly treacherous currents in

the wreckage-strewn channel made continued search efforts on the

river too risky to continue overnight.

Starting at 6 a.m. (1000 GMT) on Wednesday, "we're hoping to

put divers in the water and begin a more detailed search to do

our very best to recover those six missing people," state police

Colonel Roland Butler told reporters late on Tuesday.

Rescuers pulled two other workers from the water alive on

Tuesday, and one of them was hospitalized. The six presumed to

have perished included workers from Mexico, Guatemala and El

Salvador, according to the Mexican Consulate in Washington.

Officials said all eight were part of a work crew repairing

potholes on Key Bridge's road surface when the Singapore-flagged

container vessel Dali, leaving Baltimore bound for Sri Lanka,

plowed into a support pylon of the bridge at about 1:30 a.m.

(0530 GMT).

A trestled section of the 1.6-mile (2.6 km) span almost

immediately crumpled into the water, sending vehicles and

workers into the river.

The 948-foot (289 m) ship had reported a loss of propulsion

shortly before impact and dropped anchor to slow the vessel,

giving transportation authorities time to halt traffic on the

bridge before the crash. That move likely prevented a higher

death toll, authorities said.

It was unclear whether authorities also tried to alert the

work crew ahead of the impact.

Maryland Governor Wes Moore said at a Tuesday news briefing

the bridge was up to code with no known structural issues. There

was no evidence of foul play, officials said.

SHIP'S SAFETY RECORD

The Baltimore wreck drew attention to the vessel's safety

record. The same ship was involved in an incident in the port of

Antwerp, Belgium, in 2016, hitting a quay as it tried to exit

the North Sea container terminal.

An inspection in 2023 carried out in Chile found "propulsion

and auxiliary machinery" deficiencies, according to data on the

public Equasis website, which provides information on ships.

But Singapore's Maritime and Port Authority said in a

statement that the vessel passed two separate foreign-port

inspections in June and September 2023. It said a faulty fuel

pressure gauge was rectified before the vessel departed the port

following its June 2023 inspection.

Video footage on social media showed the vessel slamming

into the Key Bridge in darkness, the headlights of vehicles

visible on the span as it crashed into the water and the ship

caught fire.

All 22 crew members on the ship, owned by Grace Ocean Pte

Ltd, were accounted for, its management company, Synergy Marine

Pte Ltd, reported.

U.S. Transportation Secretary Pete Buttigieg said closure of

the port would have a "major and protracted impact to supply

chains." The Port of Baltimore handles more automobile freight

than any other U.S. port - more than 750,000 vehicles in 2022,

according to port data, as well as container and bulk cargo

ranging from sugar to coal.

Still, economists and logistics experts said they doubted

the port closure would unleash a major U.S. supply chain crisis

or major spike in the price of goods, due to ample capacity at

rival shipping hubs along the Eastern Seaboard.

The loss of the bridge also snarled roadways across

Baltimore, forcing motorists onto two other congested harbor

crossings and raising the specter of nightmarish daily commutes

and regional traffic detours for months or even years to come.

The bridge, named for the author of the Star-Spangled

Banner, carries about 31,000 vehicles across the harbor daily

and serves as the main route for motorists between New York and

Washington seeking to avoid downtown Baltimore. It opened in

1977.

President Joe Biden promised on Tuesday to visit Baltimore,

40 miles (64 km) away, as soon as possible and said he wanted

the federal government to pay to rebuild the bridge.

National Transportation Safety Board chair Jennifer Homendy

said a team of 24 agency personnel were on the scene to

investigate the accident. She said Singapore safety personnel

would arrive in Baltimore on Wednesday.

Tuesday's disaster may be the worst U.S. bridge collapse

since 2007, when the I-35W bridge in Minneapolis plunged into

the Mississippi River, killing 13 people.