What actually went right amid a tragedy: How heroic professionals did their job just before the Baltimore bridge collapse

• Certain factors may have minimized lives lost in the Baltimore bridge collapse.
• Police halted traffic quickly, the collision occurred overnight, and rescue efforts were robust.

Two people were killed, and four are missing and presumed dead after a cargo ship collision caused the shocking collapse of Baltimore's Francis Scott Key Bridge — and authorities and marine experts say it could have been much, much worse.

But lives were saved thanks to a number of things that fell into place early Tuesday morning: quick thinking by the ship's crew and port authority police, an emergency comms system that appears to have worked as intended, and a whole lot of luck.

A key factor was the distress call, maritime experts told Business Insider.

The crew of the Singapore-tagged Dali container ship issued a mayday after they reportedly lost propulsion, giving authorities controlling the bridge a critical period of about 90 seconds to stop more vehicles from crossing the span.

Radio recordings reveal just how little time the Baltimore Port Authority police had.

At 1:27 a.m., a police officer can be heard ordering other cops to shut down traffic.

"I need one of you guys on the south side, one of you guys on the north side. Hold all traffic on the Key Bridge," the officer said. "There's a ship approaching that's just lost their steering."

As police confirmed the orders, the officer also said to contact the foreman of a work crew on the bridge and get them off "immediately."

But seconds later, the bridge collapsed. Rescue crews spent Tuesday and Wednesday looking for survivors in the frigid Patapsco River.

On Wednesday, authorities announced they had found the bodies of two people inside a submerged pickup truck. Four other men remain missing.

In seconds, authorities saved lives

Kevin Battle, the harbor master of Portland Harbor in Maine, told BI he was "amazed" that police could halt traffic to the bridge as quickly as they did.

"It was horrific what happened, but it could have been worse — there's no telling how many lives were saved by their quick responses," he said.

The mayday would have alerted all traffic around the 984-foot vessel that it was in trouble. That call would likely have been followed with a description of the distress that was occurring, Eric Dawicki, president of the Northeast Maritime Institute, told Business Insider.

Sounding the alarm appears to be what got word to those in charge of the bridge, he said.

"When they made that call, the bridge attendants did a remarkable job of stopping flow of traffic on each end. And that's what truly saved lives. They are truly the unsung heroes of this event," Dawicki said.

Andy Middleton, director of the Apostleship of the Sea in Baltimore, a Catholic ministry for seafarers, told BI he spent time with two members of the crew before they departed on what was to be a 28-day voyage, taking them to a nearby Walmart on Monday to buy personal items.

He said his brief interactions with the crew — as well as his 15 years providing aid to seafarers — leads Middleton to believe every effort was made to avoid what happened.

The crew dropped the ship's anchor to try to prevent a collision with the bridge support, according to the Maritime and Port Authority of Singapore, where the vessel was flagged.

"I can't imagine that under the circumstances, if they had an opportunity to save lives or minimize damage that they wouldn't have done it," Middleton said. "The fact that there was a mayday call made would be in line with what I think is the character of seafarers."

Captain James Staples, a principal at consultancy OceanRiverLLC, said the mayday call didn't leave sufficient time to keep all cars from crossing the 1.6-mile-long bridge.

Still, it prevented many cars from getting on. Issuing the distress call is an essential step the pilot could have forgotten in the chaos, he said.

Beyond the alert to authorities, the Coast Guard's search and rescue effort was fast enough to pull two people from the water.

"They were right on the scene immediately and making sure that they could be there to retrieve any survivors," Dawicki told BI. "They've just done an outstanding job."

Philip Schifflin, the director of the Center for Mariner Advocacy at The Seaman's Church Institute, told BI the "robust" and "thorough" search and rescue efforts he observed through news coverage made it likely that all those who could have been saved were.

"If there was somebody on the surface of the water alive, they likely would've been found and recovered," he said.

Another mundane factor: timing.

The bridge was struck and collapsed early Tuesday morning, when there was little car traffic on the span. Video from the incident shows cars passing over the bridge seconds before the crash, and a local man crossed the bridge after an argument with his girlfriend moments earlier, The Telegraph reported.

Had the ship collided with the bridge during daylight hours or, worse, during rush hour, it's likely the number of casualties would have been far higher.

Training and technology can help limit disasters

Crews train for a loss of propulsion and steering, among other scenarios, Captain Michael Campbell with Massachusetts Maritime Academy told BI. He cautioned that it's too early to say what went wrong on the cargo vessel, called Dali. "I've talked to marine engineers and other captains and people were all speculating what went on. And you can't tell by the video," he said.

The Dali also crashed at a port in Europe in 2016.

Yet when a crisis does emerge, having drilled on how to respond can save lives, Campbell said. "The big thing is with training — the more repetition — it becomes second nature. It's not, 'OK, what do I do now?'" he said.

Campbell said many operators in the maritime industry conduct quarterly run-throughs for situations such as a steering failure.

Ships heading for or leaving port must conduct systems tests within 12 hours of sailing. This includes checking propulsion and steering systems and other electronics, maritime experts told BI.

Dawicki, from the Northeast Maritime Institute, said students at the college undergo extensive training — from first aid to emergencies they might expect to face at sea. It's prescribed in part by an international treaty for professional mariners whether the ship is based in the US or elsewhere.

Campbell also said the technology on ships is much improved from when he started his career in the 1980s. There are safety systems — often brought about or beefed up due to earlier mishaps — and technology like GPS and widespread automation that have improved how ships operate, he said. "You're not relying on somebody going and turning a valve or something," Campbell said. "Things are more controlled."