A container ship struck a major bridge in Baltimore early Tuesday, causing it to plunge into the river below. From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collision, 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.

The deadliest of those in the U.S. came on Sept. 22, 1993 when barges being pushed by a towboat in dense fog hit and displaced the Big Bayou Canot railroad bridge near Mobile.

Minutes later, an Amtrak train with 220 people aboard reached the displaced bridge and derailed, killing 47 people and injuring 103 people.

The train had been running about 30 minutes late because of an air conditioning problem that was repaired in New Orleans.

Around the same time, Willie Odom was piloting the towboat Mauvilla as it pushed six barges away from a wharf in Mobile and up the winding Mobile River. The journey would take the boat northward into the Mobile-Tensaw Delta.

With the landscape shrouded in fog, a confused Odom unknowingly turned off the river into Big Bayou Canot, a narrow, non-navigable waterway that snakes through the delta and is crossed by a railroad bridge that lacked lights. As Odom tried to find a tree to tie up until the fog lifted, records show, a barge struck a bridge support, bending the rail tracks more than one yard out of line just eight minutes before the Amtrak train arrived.

Traveling at 72 mph (116 kph), the lead locomotive reached the bridge and jumped the track at the spot where the rails were bent by the barge collision. The 3,000-horsepower, 240-ton engine flew across the bayou, embedding in about 46 feet of mud on the opposite bank. Two other locomotives followed it into the water, along with a baggage car, a crew dorm car and two passenger coaches.

Once survivors and victims were plucked out of a river delta so remote it’s called “America’s Amazon,” the National Transportation Safety Board opened an investigation. The agency held a public hearing in Mobile, just miles from the bayou, made multiple recommendations to improve safety.

In Baltimore today, it is not clear what caused the cargo ship to crash into the Francis Scott Key Bridge long before the busy morning commute in what one official called a “developing mass casualty event.”

Two people were rescued, and it was not clear how many more might be in the waters of the busy harbor near a key port.

The ship crashed into one of the bridge’s supports, causing the structure to break apart like a toy. It tumbled into the water in a matter of seconds — a shocking spectacle that was captured on video and posted on social media. The vessel caught fire, and thick, black smoke billowed out of it.

“Never would you think that you would see, physically see, the Key Bridge tumble down like that. It looked like something out of an action movie,” said Baltimore Mayor Brandon Scott, calling it “an unthinkable tragedy.”

Fire Chief James Wallace said authorities “may be looking for upwards of seven people” but said that number could change and other officials wouldn’t give figures. It was not clear if the two rescued were included in the seven cited by the fire chief.

AL.com contributed to this report.