BALTIMORE, March 27 (Reuters) - The pilot of the cargo

freighter that knocked down a highway bridge into Baltimore

Harbor had radioed for tugboat help and reported a power loss

minutes earlier, federal safety officials said on Wednesday,

citing audio from the ship's "black box" data recorder.

The head of the National Transportation Safety Board also

said that Francis Scott Key Bridge, a traffic artery over the

harbor built in 1976, lacked structural engineering redundancies

common to newer spans, making it more vulnerable to a

catastrophic collapse.

New insights into the fatal disaster emerged a day after the

massive Singapore-flagged container ship Dali sailing out of

Baltimore Harbor bound for Sri Lanka reported losing power and

the ability to maneuver before plowing into a support pylon of

the bridge.

The impact brought most of the bridge tumbling into the

mouth of the Patapsco River almost immediately, blocking

shipping lanes and forcing the indefinite closure of the Port of

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

Divers on Wednesday recovered the remains of two of the six

workers missing since the crumbling bridge tossed them into the

water, officials said on Wednesday.

Maryland State Police Colonel Roland Butler said a red

pickup truck containing the bodies of the two men was found in

about 25 feet (7.62 m) of water near the mid-section of the

fallen bridge.

He also said authorities had suspended efforts to retrieve

more bodies from the depths due to increasingly treacherous

conditions in the wreckage-strewn harbor. Butler said sonar

images showed additional submerged vehicles "encased" in sunken

bridge debris, making them difficult to reach.

The two men whose bodies were recovered on Wednesday were

identified as Alejandro Hernandez Fuentes, 35, of Baltimore, a

native of Mexico, and Dorlian Ronial Castillo Cabrera, 26, of

nearby Dundalk, originally from Guatemala.

Four more workers who were part of a crew filling potholes

on the bridge's road surface remained missing and presumed dead.

The six also included immigrants from Honduras and El Salvador,

officials said.

Rescuers pulled two workers from the water alive on Tuesday,

and one was hospitalized.

The economic fallout could be staggering. The port handles

more automobile and farm equipment freight than any other in the

country, as well as container freight and bulk goods ranging

from sugar to coal.

U.S. Transportation Secretary Pete Buttigieg said the 8,000

jobs are "directly associated" with port operations, which

generate $2 million a day in wages.

Still, economists and logistics experts doubted the port

closure would trigger a major U.S. supply chain crisis or

significant spike in the price of goods, due to ample capacity

at rival shipping hubs along the East Coast.

The collapse, which occurred at 1:30 a.m., has created a

traffic quagmire as well for Baltimore and the surrounding

region.

INTERVIEWING SURVIVORS

Earlier on Wednesday an NTSB team boarded the idled

freighter, still anchored in the harbor channel with part of the

mangled bridge splayed over its bow, to begin interviewing the

ship's two pilots and 21 regular crew members who remained on

the vessel, safety board chief Jennifer Homendy said.

Investigators also began reviewing information collected

from the ship's Voyage Data Recorder, including radio traffic

between the pilot and shore-based authorities leading up to the

disaster.

The pilot was heard calling for tugboat assistance several

minutes before the crash, the first indication of distress to

harbor officials, followed by a radio report that the ship had

lost all power and was approaching the bridge, NTSB officials

said at a news briefing on Wednesday night.

Video footage that captured the accident show the ship's

lights winking off, then back on briefly before the vessel's

lights go out again.

Homendy said recorder data was "consistent with a power

outage" but that an actual blackout had yet to be confirmed.

The recorder also picked up commands to the crew to drop

anchor, presumably aimed at slowing the vessel.

Safety board investigator Marcel Muise said data showed the

Dali, measuring about three football fields in length and piled

high with shipping containers, was moving at about 8 miles per

hour (12.8 km) when it struck a bridge abutment.

Homendy noted that the bridge, while deemed to be in

"satisfactory" condition from its most recent inspection in

2023, was constructed in such a way that failure of one

structural member "would likely cause a portion of, or the

entire bridge to collapse."

Further details of last-minute efforts to save lives emerged

on Wednesday from open-source recordings of emergency radio

chatter from the moments that authorities were alerted that the

cargo ship Dali was drifting out of control toward Key Bridge.

"Hold all traffic on the Key Bridge. There's a ship

approaching that just lost their steering," someone is heard

saying over a police radio.

While voices were heard discussing next steps, including

alerting any work crews to leave the bridge, one broke through

to say: "The whole bridge just fell down!" The audio was carried

by the public streaming service Broadcastify.

The U.S. Coast Guard's first priorities are to restore the

waterway for shipping, stabilize the crippled vessel and

extricate it, Vice Admiral Peter Gautier said at a White House

news briefing.

Of the ship's 4,700 cargo containers, 56 hold hazardous

materials but there is no threat to the public, Gautier said.

Two containers went overboard during the crash but they did not

contain hazardous materials. The ship was carrying more than 1.5

million gallons of fuel oil, Gautier added.

Homendy said some of hazmat containers aboard the vessel had

been breached and a sheen was noticed on the water's surface.