What we know about the tragic ship-caused collapse

Here’s what we know so far about the collapse:

What exactly happened?

The operators of the Dali cargo ship issued a mayday call that the vessel had lost power moments before the crash, but the ship still headed toward the span at “a very, very rapid speed,” Maryland Gov. Wes Moore said.

The 985-foot-long (300-meter-long) vessel struck one of the 1.6-mile (2.6-kilometer) bridge’s supports, causing the span to break and fall into the water within seconds.

Six construction workers who were filling potholes on the bridge are presumed dead. Jeffrey Pritzker, executivevice president of Brawn er Builders, said they were working in the middle of the span when it came apart.

An inspection of the Dali last June at a port in Chile identified a problem with the ship’s “propulsion and auxiliary machinery,” according to Equasis, a shipping information system. The deficiency involved gauges and thermometers, but the website’s online records didn’t elaborate.

The most recent inspection listed for the Dali was conducted by the U.S. Coast Guard in New York in September. The “standard examination” didn’t identify any deficiencies, according to the Equasis data.

The ship was moving at 8 knots, which is roughly 9 mph (15 kph).

Given the vessel’s massive weight, it struck the bridge support with significant force, said Roberto Leon, a Virginia Tech engineering professor.

“The only way the post can resist it is by bending,” Leon said. “But it cannot absorb anywhere near the energy that this humongous ship is bringing. So it’s going to break.”

Last June, federal inspectors rated the 47-yearold bridge in fair condition. But the structure did not appear to have pier protection to withstand the crash, experts said.

“If a bridge pier without adequate protection is hit by a ship of this size, there is very little that the bridge could do,” Leon said.

Federal and state investigators have said the crash appears to have been an accident.

How many people are missing?

Two people were rescued, and six others are missing and presumed dead. They all were part of a construction crew that was repairing potholes on the bridge. Divers searched the waters Wednesday through twisted bridge metal, a mission authorities said had turned from rescue to recovery.

People from Guatemala, Honduras and Mexico are among the missing, according to diplomats from those countries.

How often does this happen?

From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collisions, with a total of 342 people killed, according to a 2018 report from the World Association for Waterborne Transport Infrastructure.

Eighteen of those collapses happened in the United States.