In 2018, President Vladimir V. Putin of Russia oversaw the inauguration of the bridge, and it delivered a humiliating setback to him. The assault, which resulted in the deaths of four individuals, was a pivotal event in the conflict, and it emphasized Russia’s incapacity to safeguard a crucial strategic resource and a powerful emblem as its sole link to Crimea.

The experts who reviewed the imagery and design of the bridge offered new details on how the operation’s success damaged the bridge, stating that it was due to a blast that was planned with sophistication and luck.

There are few direct comparisons to such an extraordinary act of sabotage on a bridge located in enemy territory during periods of war.

Retired Rear Adm. Samuel J. Cox, the director of the Naval History and Heritage Command in Washington, remarked that the damage inflicted upon the Kerch bridge is rather remarkable considering the historical challenges. He further noted that demolishing bridges used to be exceedingly challenging prior to the introduction of precision-guided weaponry, and even with such advancements, it remains a formidable task.

In the event that it hits in the incorrect location, even a potent explosion might cause minimal harm. In order to endure unforeseen pressures, like a weather occurrence, bridges are engineered with additional resilience beyond their usual requirements.

There is nothing unusual about the design of the Kerch Strait Bridge, except for the fact that a portion of the bridge is raised, allowing traffic to pass underneath. The roadway is held up by long steel girders resting on reinforced concrete piers sunk into the sea floor, spanning about 11 miles in length.

Following its annexation of Crimea, the bridge was inaugurated in 2018 as a symbolic connection to Russia, detested by Ukrainians. Lately, it has played a vital role as a supply route for the Russian military campaign.

According to experts who analyzed images of the explosion, there are suggestions that the destruction was a result of a missile launched from a boat beneath the bridge, as stated by Ukrainian officials, instead of a truck bomb.

They also concurred that the position of the truck when it veered off could have reduced the damage and was vital, causing the collapse of the roadbed between the two supports.

“Many factors needed to align perfectly for this to occur,” stated Vijay K. Saraf, a leading engineer at Exponent.

On the side of the bridge that leads to Russia, in one of the extended and lower parts, the explosion was strategically positioned to cut off or obliterate approximately 900 feet of uninterrupted road. The explosion set fire to a train that was transporting sizable fuel containers on a nearby bridge, resulting in flames and a column of smoke. The destruction was not limited to the area between the supports on the road surface. It appeared to have been executed with the accuracy of a controlled demolition.

However, the specialists disagreed on whether the sequence indicated an advanced strategy.

According to Adam Evans, a structural engineer at Wiss, Janney, Elstner Associates, it seemed improbable that the explosion was deliberately timed at a favorable location to cause harm to the roadway. It was conceivable that the orchestrators of the assault anticipated the fuel tanks to detonate and cause significant harm to the railway bridge.

” ‘We’ll transport an explosive device across this bridge and we’ll inflict a significant amount of destruction,’ ” Mr. Evans stated. “I believe it’s more plausible to say that I would find it difficult to believe that.”

Several engineers stated that if the bomb had been larger, the explosion could have caused greater damage to the section of the bridge, which was already raised up by the soaring steel arches. The truck had already started to incline up the steep slope a minute or two later, or maybe even one minute, after the bomb had gone off.

Engineers say that a sufficiently powerful explosion in that location could have potentially harmed the arches and rendered the entire bridge impassable.

Nair Shankar, a structural engineer based in Chicago with over 50 years of experience in designing bridges, stated that this appears to be a nearly catastrophic mistake if it turns out to be true.

That raises inquiries regarding the timing of the explosion and whether the driver of the truck was aware of the explosive device.

He said that it would be difficult to remotely detonate the enormous amount of steel it took to hit the arch directly from a longer distance. Mr. Nair said that a suicide bomber might have expected to hold off until the truck made it to the arched span. It could be challenging to time the remote detonation precisely.

“If it were a suicide truck explosion,” Mr. Nair stated, “I would assume the individual would have demolished the primary section.”

The curved portion of the bridge, it remains uncertain whether the truck explosive that was utilized was sufficiently substantial to cause its collapse. Self-destructive attackers frequently exhibit unpredictable behavior, yet the cause for the explosive remains unidentified.

According to the British Ministry of Defense, Russian officials stated that road and rail traffic could be disrupted until September 2023. A recent satellite image taken by Planet last week indicated that a large section of the roadway is still missing. However, it is possible that the bridge parts will be restored quickly, allowing traffic on both the road and rail to return to full capacity next year.

During the conflict, the Kremlin experienced a decline in momentum, resulting in a symbolic triumph for the Ukrainians and a humiliating setback for the bridge. Irrespective of the extent of the damage sustained, the attack proved successful.

According to Professor Nick Glumac, an engineering professor at the University of Illinois at Urbana-Champaign, experts have stated that the size of the fireball can indicate the quantity of explosives in the truck, with a few tons or less being a smaller charge and a larger quantity indicating a greater charge, depending on the type of explosive.

The beams are particularly susceptible, positioned in the section where they are most inclined to bend when subjected to pressure. This location, right in the center of the explosion, subjected the bridge’s girders to immense pressure due to the downward force of the blast. These girders are composed of steel beams that support the roadway, and they experienced significant strain when the bomb detonated.

The span collapsed and they yielded, which might have also torn off a portion of the steel. Certain visuals of the destruction imply that the truck detonated right above one of those beams.

As per engineers, the road beneath the explosive was a connected framework spanning across five of the support pillars, encompassing approximately 900 feet. However, the destruction was considerably more widespread than just that particular area.