Thirty Times the Threshold: The Francis Scott Key Bridge Collapse of 2024 and the Case for Vessel-Collision Risk Assessment of India's Bridges, Ports and Approach Channels

B.A.P-I Retrospective, 2020 to 2024. This paper looks back at 2024 and the lesson it holds for the protection of India's critical infrastructure.

1. Introduction

At about 0129 local time on 26 March 2024 the Singapore-flagged container ship Dali, 984 feet long and outbound from Baltimore, struck Pier 17 of the Francis Scott Key Bridge, a pier standing about 200 feet from the channel edge, and the bridge collapsed (NTSB, 2025, Nov. 18b). Six members of a highway maintenance crew were killed. The images of a continuous steel truss folding into the water in seconds travelled around the world, and in India they were watched with particular attention, because the ship's crew were Indian; they were tested for drugs and alcohol before and after the incident, with no positive results (India Sea Trade News, 2024, May 15).

With hindsight, and with the final report of the United States National Transportation Safety Board (NTSB) now available, the collapse can be read for what it was: not a freak accident but a known risk that had never been measured. This paper reviews what the NTSB found and asks what the event means for the protection of bridges, ports and approach channels in India.

2. A Single Loose Wire and a Chain of Blackouts

The NTSB determined that the probable cause was a loss of electrical power due to a loose signal wire connection to a terminal block, a wire that had never been fully seated because wire-label banding prevented its insertion into a spring-clamp gate (NTSB, 2025, Nov. 18a). When the wire backed out, a breaker opened, low-voltage power was lost, and with it went lighting, cooling and steering pumps, propulsion and steering. A flushing pump that the crew had been using to supply fuel to the generators lacked redundancy and did not restart automatically, causing a second blackout; the breakers had been left in manual rather than automatic mode, which stretched the first blackout from about 10 seconds to 58 seconds; and infrared thermal imaging during maintenance might have revealed the loose connection (NTSB, 2025, Nov. 18b). The Board found that the engineering crew's initial restoration of low-voltage power was timely and that the pilots and bridge team also responded in time; without propulsion, however, no response could alter the ship's heading (NTSB, 2025, Nov. 18b). The Indian crew, in other words, did what could be done; the failure lay in the ship's equipment and in the bridge's lack of protection.

One finds in this sequence the classic anatomy of a cascading failure. No single component was dramatic; each failure was small, and each was permitted by a design or maintenance choice that had seemed harmless. The lesson for infrastructure operators is that redundancy in critical systems, which the NTSB found could reduce risk in restricted waters, matters most in precisely those few minutes when a large vessel is closest to fixed infrastructure.

3. The Bridge That Was Never Assessed

The more consequential finding, for so far as infrastructure protection is concerned, related not to the ship but to the bridge. In March 2025 the NTSB reported that the Key Bridge had been almost 30 times above the acceptable risk threshold set by guidance of the American Association of State Highway and Transportation Officials (AASHTO) for critical or essential bridges. It identified 68 other bridges in 19 states, designed before that guidance and lacking a current vulnerability assessment, and asked their 30 owners to calculate the annual frequency of collapse and, where the threshold was exceeded, to adopt risk reduction plans; AASHTO had published the method in 1991 and repeated its recommendation for existing bridges in 2009 (NTSB, 2025, Mar. 20).

The final report made the point sharper. Among the contributing factors were the lack of countermeasures to reduce the bridge's vulnerability to vessel impact, which an AASHTO vulnerability assessment would likely have revealed, and the lack of effective, immediate communication to warn the highway workers (NTSB, 2025, Nov. 18b). The Board noted that the bridge opened in 1977, that in 1980 the 390-foot Blue Nagoya had struck it with only minor damage, and that the Dali was about ten times that size; the Maryland Transportation Authority (MDTA), like many bridge owners, had likely been unaware of the risk (NTSB, 2025, Nov. 18a). The bridge had not changed. The ships had.

4. Seconds That Saved Lives, and Seconds That Did Not

Within the tragedy there was a demonstration of what works. A pilot contacted shoreside dispatch about a minute after the first power loss, MDTA police at both ends stopped traffic, and the bridge was cleared of vehicles about 48 seconds before the ship struck; the NTSB found that this quick action prevented greater loss of life, and that notifying the workers at the same moment might have given them time to reach an intact section (NTSB, 2025, Nov. 18b). The difference between the motorists who were stopped and the workers who were not is the whole argument for warning systems that are designed rather than improvised.

The economic cost was large and lasting. The Fort McHenry Federal Channel was restored to its full 700-foot width and 50-foot depth only on 10 June 2024, after about 50,000 tons of wreckage were removed by an effort involving some 56 agencies and 1,587 responders (Mitchell, 2024, Jun. 10). The replacement bridge is now estimated at US$4.3 billion to US$5.2 billion, with opening expected in late 2030, against an original estimate of about US$2 billion (Thompson, 2025, Dec. 11).

5. Why India Should Read the NTSB Report Closely

India's maritime ambitions make the lesson timely. Indian ports now host the largest ships afloat: in April 2025 the 24,346 TEU MSC Turkiye, 399.9 metres long, berthed at Vizhinjam (Free Press Journal, 2025, Apr. 9), a milestone for India's transhipment capability. Every new sea link, creek crossing or river bridge over navigable water will have to stand for decades against such vessels, and against the larger ones that will follow. Confined channels have already shown what a loss of control can do. In August 2026 the 147-metre container ship Nawata Bhum, bound for Kolkata, failed to negotiate a bend in the Hooghly near Diamond Harbour and struck the embankment, with a suspected steering problem among the possible factors (Marine Insight, 2026, Aug. 14). Earlier, in 2019, a coal barge broke free of its anchor in the Hooghly and drifted into the concrete structure protecting the piers of Vidyasagar Setu; the engineers reported that the pier itself was unaffected (Roy, 2019, Aug. 3). That outcome was the product of pier protection doing its job.

What comes through from all of this is that India already has protective structures in place on crossings such as Vidyasagar Setu and the engineering institutions to extend them. The natural next step is a systematic national assessment, published in a common format, of how each bridge over a navigable channel performs against the largest vessels now using it. The Baltimore question, what is the collapse frequency of this bridge against today's ships, is one that every Indian port and bridge authority can and should be equipped to answer.

6. Assess Every Crossing: A Vessel-Collision Protection Agenda for India

Keeping this into consideration, four measures are recommended. First, a mandatory vessel-collision vulnerability assessment should be carried out for every bridge over a navigable channel, port approach or national waterway, repeated whenever the design vessel calling at the port changes, with results reported to a national authority. Second, where risk exceeds the threshold, owners should be obliged to install countermeasures such as protective islands, dolphins or fender systems, or to restrict the size and conditions of vessel transits. Third, port control, pilots and bridge operators should share a single alarm, so that a blackout or steering failure near a crossing stops road traffic and alerts workers automatically and simultaneously. Fourth, ports should require redundancy in propulsion and steering power, and thermal-imaging maintenance checks, for large vessels transiting near fixed infrastructure.

These measures belong within a wider architecture in which critical infrastructure protection is treated as a dimension of national security in its own right (Dash, 2025, Jan. 30), and in which bridges, ports and channels can be scored on measurable resilience indicators of the kind proposed in the Bharat National Resilience Index (Dash, 2025, Oct. 28). Baltimore's bridge stood for nearly half a century while the ships passing under it grew tenfold. The calculation that might have saved it was available since 1991. India, with its growing ports and its engineering depth, is well placed to make that calculation a national standard.