Inside Baltimore Key Bridge's history - from being built in the '70s to officials refusing to install pier guards after 9/11 because it was 'too expensive' before shock container ship crash

The shocking collapse of a bridge in Baltimore on Tuesday led to a frantic rescue effort, with at least six people presumed dead - but has also raised questions about the integrity of the structure.

The disaster stemmed from a container ship hitting the historic overpass - bringing it to an abrupt end after some 47 years. Formerly The Francis Scott Key Bridge, it was the third longest crossing of its kind.

Measuring in at 1,200 feet, it was named after the writer of The Star-Spangled Banner, due to the fact it stood some 100 yards of where Francis Scott Key saw the British bombardment of Fort McHenry in 1814 - the battle that inspired the patriotic poem.

Its last inspection came in May 2021, which found that - despite being held up by just three support beams - it was in fair condition. 

After the terrorist attacks on 9/11, city officials elected not to install pier guards around those beams, calling the undertaking too expensive. A boat hit one of those beams Friday night, causing a collapse that erased the structure in seconds.

Its history, however, remains, and leaves behind a lasting legacy.

The bridge was opened on March 23, 1977, after five years of construction.

Workers broke ground after city officials found a need for a second crossing over the famed Baltimore Harbor, due to increased levels of traffic on the earlier Baltimore Harbor Thruway and Tunnel.

This came at a time when the port was growing into one of the busiest in the country, rivaled only by counterparts in New York and LA.

Upon its completion, The Francis Scott Key Bridge - commonly shortened to the Key Bridge - quickly became an integral part of Interstate 695, carrying motorists north and south between Baltimore's Harbor and Chesapeake Bay.

Also known as 'The Baltimore Beltway,' I-695 extends all the way around the city of Baltimore, which back in '77, had more than three times the residents than it does today.

The decrease in population was likely due to the amount of jobs that have left the city since - though the Key Bridge during that span still stood tall.

But more importantly, it was long - some 1.6-miles to be exact - and was a steel-arch continuous through truss bridge, meaning it extended without hinges across three or more supports. It had a span of 1,200 feet between each pier.

In the years since its construction, several hundred continuous through truss bridges have been built across the U.S., though only one - the Astoria-Megler Bridge in Astoria, Oregon - is longer than the late one in Baltimore in terms of its span.

The other structure, the Ikitsuki Bridge, like most continuous through trusses these days, is in Japan - more specifically Nagasaki - where it spans some 1,312 feet.

The one in Oregon, meanwhile, measures in at 1,232 feet - a few yards short of the Key.

However, even before the Key's destruction, other continuous through truss bridges have been the victims of disaster.

A 2012 study featured in the Journal of Constructional Steel Research cited how the the steel truss bridge I-35W over the Mississippi River in Minneapolis 'suddenly collapsed on the 1st of August 2007,' killing 13 people and injuring 145. 

The NTSB later determined a design flaw was the likely reason for the collapse and that additional weight on the bridge at the time contributed to the catastrophic failure.

In Japan, the study's authors wrote that there is also a litany of aging truss bridges, 'and they need prompt inspection, reinforcement and maintenance. 

'On the Kiso River Bridge (in the Chubu region, roughly 144 miles long) and the Honjo Bridge (in Honjo) the diagonal member penetrates the reinforced concrete slab and it fractured because of corrosion,' authors wrote.

The Key bridge's collapse occurred Tuesday around 1:40am, after a cargo boat sailing out of Singapore plowed into one of these support beams, which had stood relatively unprotected since the bridge's opening in March of '77.

It carried more than 12.4 million commercial and passenger vehicles a year, with some 7,448 vehicles traversing in its first 11 hours of operation.

In the early days, tolls were 75 cents for cars, and a mere 50 cents an axle for trucks.

In the years since, the bridge left an indelible mark on the city of Baltimore, featured in Baltimore-set shows like The Wire, which aired on HBO.

In addition to its icon status, the four-lane roadway offered impressive sights along the entrance to the Baltimore harbor, allowing motorists to take in not just the city's downtown, but Fort McHenry, Canton, the Inner Harbor, the hills of Catonsville, Towson’s high rises and the tower near Druid Hill Park as well.

President Bill Clinton appeared before it during an address in Baltimore in August 1995, where he assailed Republican environmental polices, and ordered shipping companies doing business with the government to report toxic chemical emissions. 

It cost $11 million to build - though, after the September 11 attacks, the then-struggling city decided to not install pier guards due to prospective costs.

In an interview with Baltimore's WBAL-TV, engineer experts slammed the decision, citing how the nearly half-century-old piers were not built to handle the force generated from such an impact, and that bumpers would have helped.

'I think they would have been effective in all this. They would have reduced the impact, or at least prevented the ship impacting directly the piers because the way it went, it looked almost effortlessly the same,' said Abieyuwa Aghayere, a civil engineering professor at Drexel University. 

'The vessel hit the pier and it just went and there was no hesitation. The bridge couldn't handle it at all. So, I think the fenders, the bumpers would help.'

'The way that it collapsed,' he continued, 'I think that was surprising to some people, in particular, because one of the piers was hit, but all three of the spans collapsed. That's a function of the continuity of the bridge.'

Rachel Sangree, an associate professor in the Department of Civil and Systems Engineering at Johns Hopkins Whiting School of Engineering said: 'There is a lot of load-sharing that goes on among those three spans, and so, if two of them are damaged or destroyed, as was the case here, by their support, direct support being removed, then the third span is going to be severely impacted and collapsed as well.'

Meanwhile, Baltimore's already reeling job market was also dealt a blow by the unforeseen collapse as it has created about 15,300 direct jobs and with nearly 140,000 jobs linked to port activities, according to Gov. Wes Moore, a Democrat.

Back in February, Moore said the port the bridge stretched over ranks first among those in the nation for volume of automobiles and light trucks, as well as heavy farm and construction equipment, and imported sugar and gypsum. 

In a Tuesday morning news conference, he insisted that the bridge was fully up to code. 

Feds and state officials are still probing the crash.