The National Transportation Safety Board (NTSB) has urged 30 bridge owners across 19 states to assess the structural vulnerability of 68 bridges at risk of collapse due to vessel strikes. This recommendation follows the ongoing investigation into the catastrophic failure of the Francis Scott Key Bridge in Baltimore, which collapsed on March 26, 2024, after being struck by the containership Dali.

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According to NTSB findings, the Key Bridge’s risk of collapse was nearly 30 times higher than the acceptable threshold set by the American Association of State Highway and Transportation Officials (AASHTO). The 68 bridges identified were built before these modern safety standards were established and have not undergone updated vulnerability assessments.

The NTSB is not declaring these bridges unsafe but is advising owners to evaluate their collapse risk using AASHTO’s Method II calculation. If a bridge exceeds the acceptable risk level, owners should implement a risk reduction plan, which may include infrastructure reinforcements or operational changes.

Federal regulations have required new bridges to be designed with vessel collision risks in mind since 1994. However, the Key Bridge, completed before these requirements, lacked a formal vulnerability assessment. The NTSB stated that had such an assessment been conducted, authorities could have taken steps to mitigate the risk.

In addition to the bridge owner recommendations, the NTSB is calling on the Federal Highway Administration, the U.S. Coast Guard, and the U.S. Army Corps of Engineers to form an interdisciplinary team to assist in evaluating and mitigating bridge vulnerabilities.

The Dali, a 984-foot Singapore-flagged cargo ship, lost power and propulsion while leaving Baltimore Harbor, striking a key support pier and causing the bridge to collapse. The incident resulted in the deaths of six construction workers and injuries to another worker and a crew member onboard the vessel.

As the investigation continues, the NTSB’s recommendations highlight the urgent need to reassess aging bridge infrastructure to prevent future tragedies.