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

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 …