Baltimore bridge collapse would have been much worse if the ship hadn't called in 'mayday'

• The cargo ship that crashed into the Baltimore bridge called in a 'mayday' moments before. 
• Thanks to the distress call, officers stopped traffic to the bridge, Maryland Gov. Wes Moore said.
• Moore said the call saved lives.

The Baltimore bridge collapse could have been deadlier had the crew of the swerving cargo ship not called in a "mayday" before hitting the bridge's support.

Maryland Governor Wes Moore told reporters at a news conference Tuesday morning that before the Singapore-tagged Dali cargo ship crashed into Baltimore's Francis Scott Key Bridge, crew members called in a distress signal.

The crew told authorities that they had lost power on the ship and were in trouble, Moore told reporters.

That call, Moore said, let officers quickly close off the bridge to car traffic on both sides, likely preventing even more casualties.

"Literally by being able to stop cars from coming over the bridge, these people are heroes," Moore said. "They saved lives last night."

Moore would not confirm if any cars were on the bridge at the time of its collapse at 1:28 a.m. on Tuesday. Crew members were working on the bridge repairing potholes when it crumbled into the Patapsco River, Senator Chris Van Hollen told reporters.

At least six people who were on the bridge are still missing, according to Paul Wiedefeld, Maryland's transportation secretary.

Two have been found alive, with one in "very serious condition," authorities said.

A video of the incident posted to X, formerly Twitter, shows the cargo ship — with its lights turning off and on — colliding with one of the bridge's support beams, causing the entire bridge to fall into the water within seconds.

Moore declared a state of emergency for Maryland as rescue teams continued searching for survivors.

Baltimore's port that the bridge spanned is one of the largest by cargo tonnage in the US.

The loss of the critical bridge, as well as a now-blocked harbor, could be a major hit to both the local economy and nearby distribution centers, including Amazon and Fedex.

Meanwhile, shares of transportation and coal-mining companies are down as news of the collapse ripples through the stock market.