The bridge was created before pier protections were standardized.
BALTIMORE -- In the wake of the collapse of Baltimore's Francis Scott Key Bridge, engineering and infrastructure policy experts explained the critical need for bridge reform in the United States and an international standard for large cargo ships.
The Key Bridge partially collapsed early Tuesday morning after a massive cargo ship collided with one of the bridge's support columns, sending vehicles into the Patapsco River below and leaving six people unaccounted for, according to officials.
Police said Wednesday that two of the victims were found dead inside a submerged vehicle.
The investigation into the cause of both the collision and the bridge collapse is ongoing, officials said.
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Rick Geddes, infrastructure policy expert and director of the Cornell University Infrastructure Policy Program, weighed in on the infrastructure and safety of the Key Bridge.
"This disaster reveals how exposed America's critical infrastructure is to sudden and devastating accidents as well as intentional destruction," Geddes said in a statement to ABC News. "I think the bridge was not designed to take the force and the mass of an enormous cargo ship directly hitting one of the pylons," Geddes said in an interview with ABC News.
Pylons, or piers, are the critical load-bearing components of cable-supported bridges, such as Baltimore's Key Bridge, a 1.6-mile-long, continuous truss-style bridge, according to Geddes.
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Modern protective measures for bridge piers include adding "fenders," which are protection systems designed to protect the bridge from vessels transiting under or in the vicinity of the bridge, according to the U.S. Coast Guard.
Fenders on modern bridges include "dolphins," which are large circular walls filled with material such as sand or concrete and "artificial islands," armored artificial islands around the piers made of a sand core that is protected against wave and current action by armored slope protection, according to the Coast Guard.
However, it is not yet known whether or not the Baltimore Key Bridge had fenders at the time of the crash.
The Maryland Transportation Authority did not immediately respond to ABC News' request for a comment.
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Transportation Secretary Pete Buttigieg also weighed in on the bridge's ability to withstand a massive cargo ship collision Wednesday, "What we do know is a bridge like this one completed in the 1970s was simply not made to withstand a direct impact on a critical support pier from a vessel that weighs about 200 million pounds," he said during a press briefing.
"Right now, I think there's a lot of debate taking place in the engineering community about whether or not any of those features could have had any role in a situation like this," Buttigieg added.
The 984-feet-long and 157-feet-wide cargo ship -- operated by Synergy Marine Group and named Dali -- was moving at a speed of 8 knots, or about 9 mph, when it struck the bridge, according to officials.
"So it's a tremendous force, that the bridge would have to be designed to absorb," Geddes said, adding, "It clearly was not designed to take that."
Construction of Baltimore's Francis Scott Key Bridge began in 1972 and finished in March 1977, according to the Maryland Transportation Authority (MDTA).
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Maria Lehman, former president of the American Society of Civil Engineers, told ABC News that older bridges are not designed with the post Panama Canal expansion ship allowances in mind.
In 2016, the Panama Canal expansion project constructed pathways -- on both the Atlantic and Pacific ends of the canal -- that are 70 feet wider and 18 feet deeper, to accommodate larger cargo ships.
Lehman said because Baltimore's Key Bridge was created with smaller cargo ships in mind, it was "inadequate for what we see with ships today."
"Pier protection on long-span bridges that have been built within the last decade are in line with what you're gonna need based on how heavy these new ships are," Lehman said.
Lehman said the news of the Key Bridge collapse Tuesday reminded her of the 1980 Sunshine Skyway Bridge collapse in Tampa, Florida, which she said was a "very similar" bridge and spurred a "base standard for pier protection" in the United States.
In May 1980, the M/V Summit Venture freighter struck a support beam on the Skyway Bridge causing a major collapse that left 35 people dead. The now 44-year-old tragedy spurred changes to the engineering of bridges that have been built since, according to Lehman.
Three years after the Skyway Bridge incident, the U.S. Department of Transportation Federal Highway Administration released a technical advisory titled "Pier Protection and Warning Systems for Bridges Subject to Ship Collisions"
In the 1983 advisory, the agency noted, "It may be extremely difficult to retrofit some existing bridge piers with protective systems. For this reason, it becomes particularly important to recognize the potential hazards from ship collisions and to locate and design piers on new bridges in such a way that the risks of collision are reduced to an acceptable level."
Baltimore's Key Bridge was constructed in 1977 and did not have the protected pier measures that bridges built in the decades since this advisory.
"Unless you're doing a major retrofit of any piece of infrastructure, you don't have to bring it up to code," Lehman said, adding that the Key Bridge collapse is a "wake-up" call for better bridge infrastructure and reform.
"I think just like Sunshine Skyway was a wake-up call, I think this is the next wake-up call," Lehman said, adding, "We're going to have to take a look closely at the results of what happened, and then work on the plan. So it never happens again."
In June 2023, Delaware River and Bay Authority (DRBA) officials announced the construction of the Delaware Memorial Bridge Protection System.
"Our goal is to take preemptive measures to prevent a commercial vessel from striking one of the bridge towers, which could cause significant damage to the bridge infrastructure and disruptions to interstate travel," Thomas J. Cook, executive director of the DRBA said in a press release.
The cost of the project is nearly $93 million, according to the release.
Rick Geddes hopes the devastation from the Key Bridge collapse will spur great reform in America's bridge infrastructure safety.
"The real possibility of a massive container ship of this size, running into a bridge pylon, and causing the bridge collapse is no longer theoretical," Geddes said. "I think a renewed effort to inspect and assess the state of a whole bunch of U.S. bridges will be the result of this accident."