Introduction

At about 1:30 a.m. on March 26, 2024, the MV Dali, a container ship departing the Port of Baltimore, struck a support tower of the Francis Scott Key Bridge in Baltimore, MD, causing the bridge to collapse into the Patapsco River. The bridge is a segment of Interstate 695—Baltimore's beltway—and spans the Patapsco shipping channel into the harbor.¹

A pothole repair crew of eight was on the bridge at the time of the collision. Two have survived; one with injuries. Authorities were able to stop traffic over the bridge right before the vessel strike. There were 23 mariners aboard the ship, and none sustained injury. A Unified Command and Joint Information Center have been established by the U.S. Coast Guard and Maryland state officials to coordinate their response and disseminate information on the incident.²

Who Owns and Controls the Ship?

The Dali is being chartered (leased) by Maersk, a Danish shipping firm that provides container shipping services worldwide in addition to other types of shipping. The ship is managed by the Synergy Marine Group³ and owned by Grace Ocean Private Ltd., both based in Singapore.⁴ The ship's crew are from India. It is flagged and homeported in Singapore and was classed (meaning certified as meeting construction and maintenance standards) by a Japanese firm, Nippon Kaiji Kyokai (ClassNK).⁵ The multitude of nationalities involved in operating and administering the ship is typical of the industry.

The ship was built in 2015 by Hyundai Heavy Industries in South Korea with a MAN-manufactured engine. It is almost 950 feet in length and about 160 feet in breadth with a capacity to carry 10,000 TEUs of containers (a TEU is a 20-foot container). It could be considered an average-sized container ship today but would be considered a large ship compared with the fleet in the late 1970s when the bridge was built. The ship had sailed from Asia through the Panama Canal and had called at Norfolk and New York before its Baltimore port call. When it struck the bridge, the ship was departing Baltimore for Sri Lanka.

How Do Ships Navigate Through Harbors?

A preliminary report stated that the ship lost power as it was approaching the bridge, meaning the ship may have lost propulsion. Two Baltimore harbor pilots were aboard the ship; harbor pilots navigate ships in and out of harbors because they have expertise with local navigation conditions. Even when harbor pilots are at the helm, the captain of the ship and the shipping line (Maersk) remain responsible for the safety of the vessel. Tugs typically assist in moving ships into and out of their berths (docking and undocking) and rarely escort ships through harbors as an emergency safety measure. This ship released the tugs before reaching the bridge, as is reportedly normal in the harbor.⁶

How Common Is It for Ships to Lose Power?

Loss of propulsion is a known and recorded occurrence in shipping. An annual review of marine incidents for vessels with a connection to the European Union (EU; EU-registered or EU-owned vessels or incidents occurring in EU waters) found that loss of propulsion surpassed vessel-to-vessel collisions as the leading cause of marine casualties from 2014 to 2022.⁷

Could Tug Escorts Have Prevented the Collapse of the Bridge?

Some observers have raised the question of whether tugs escorting the ship under the bridge could have prevented the ship from hitting one of the towers.⁸ After the ship reportedly lost power, the pilot called for tug assistance moments before striking the bridge, but by then it was too late for the tugs to reach the ship again.⁹ Tugs have the ability to push ships in a desired direction and even stop ships over some distance, but they must have sufficient engine power and have other design features specifically for this purpose.¹⁰

Some harbors require tug escorts but they appear to be exclusively for tankers of liquid bulk cargoes, such as oil, chemicals, or liquid natural gas (LNG). The requirements are not intended to specifically prevent bridge strikes but rather to prevent any event that might result in a spill, such as a tanker grounding. Tug escorts are a federal requirement in Prince William Sound, Alaska, and in Puget Sound, Washington.¹¹ The State of California requires tug escorts of tankers in its harbors per state regulation.¹² However, requiring tug escorts can introduce additional risk exposure simply due to the mere presence of more vessels on the water.¹³ For instance, in January 2023, one of five tugs assisting an empty tanker into the Port of Corpus Christi accidently got caught in the tanker's propeller.¹⁴ The National Transportation Safety Board's (NTSB's) forthcoming report on the MV Dali strike may provide insights into the safety benefits and drawbacks of tug escorts.

In 2000, the U.S. Supreme Court distinguished federal regulations concerning the safe operation of tankers in harbors from nonfederal requirements that can be imposed if they do not conflict with federal requirements and are based on "the peculiarities of local waters."¹⁵ State proposals concerning ship safety could also interfere with international treaties that have established global standards. While local requirements for tug escorts are allowed, ports may be reluctant to require them because of their cost and the heightened competition for containerized cargo.

How Is Port Traffic Affected?

The Port of Baltimore was the 17^th busiest port by total tonnage in the United States in 2021, the most recent year for which data are available.¹⁶ It was the 10^th busiest by dry bulk tonnage and the 15^th busiest container port in TEUs. According to the Maryland Port Administration, the port ranks "first among the nation's ports for autos and light truck volume, roll on/roll off farm and construction machinery, and imported gypsum."¹⁷ It is also "responsible for nearly $3.3 billion in personal wages and salaries, $2.6 billion in business revenue[,] and nearly $400 million in state and local tax revenue annually."¹⁸

Containers currently at the port awaiting export could be moved to other ports by truck or rail; one of the Port of Baltimore's two container terminals is served by on-dock rail access. Dry bulk—such as coal,¹⁹ the largest commodity by volume handled by the port—and roll on/roll off machinery may be more difficult to move through other ports, as specialized facilities are needed for loading and unloading. The closest large ports to Baltimore are Wilmington, DE; Philadelphia, PA; and Camden, NJ, all of which may be accessed via the Chesapeake and Delaware Canal provided the vessels have a shallow enough draft. Another nearby port, not draft restricted, is the port of Norfolk near the entrance to the Chesapeake Bay.

Following the collapse, large commercial vessels were unable to enter or exit the Port of Baltimore; 11 vessels were trapped in port as a result. The U.S. Coast Guard shipyard at Hawkins Point²⁰ on Curtis Bay is also upriver from the bridge, and six vessels of the U.S. Department of Transportation's Ready Reserve Force (available to provide surge sealift capacity to the Department of Defense, if needed) were berthed in Baltimore as of January 2024 and presumably were unable to exit the port.²¹

When Will the Port Reopen?

The U.S. Army Corps of Engineers (USACE) is managing bridge debris removal for the congressionally authorized 50-foot-deep navigation channel, initially using existing USACE Baltimore Harbor and Channels project funds.²² USACE is employing both federal and contracted assets and expertise (e.g., U.S. Navy Supervisor of Salvage and Diving team and heavy-lift cranes). USACE released a tentative timeline on April 4, 2024, which would see temporary channels established until the reopening of the permanent 50-foot-deep and 700-foot-wide federal navigation channel by the end of May.²³

The first temporary alternate channel opened on April 1, 2024, to the northeast of the (blocked) main channel, with a controlling depth of 11 feet and vertical clearance of 95 feet.²⁴ A second temporary channel was opened on April 2 to the southwest, with a controlling depth of 14 feet and a vertical clearance of 124 feet.²⁵ A third temporary channel opened on April 19 with a controlling depth of 20 feet.²⁶ A fourth temporary channel opened on April 25 with a controlling depth of 35 feet, running along one edge of the federal channel.²⁷ (See Figure 1.)

Figure 1. Baltimore Harbor Federal and Temporary Alternate Channels

Source: Prepared by CRS; Key Bridge Response 2024, "UPDATE 15: Unified Command Opens Limited Access Deep Draft Channel," press release, April 25, 2024, https://www.keybridgeresponse2024.com/post/update-15-unified-command-opens-limited-access-deep-draft-channel; original photograph by WJLA/AP via CNN, https://www.cnn.com/us/live-news/baltimore-bridge-collapse-03-26-24-intl-hnk/h_2857cadcd511caaec6a16decf811bcc2. Note: Channel boundaries are not to scale.

The deeper temporary channels have allowed some commercial traffic to resume. The bulk freighter Jonathan delivered a load of raw sugar to the Domino Sugar refinery in Baltimore using the 20-foot channel on April 25, and 4 of the 11 trapped commercial vessels were able to leave the port using the 35-foot channel the next day.²⁸ The 35-foot channel remained open for four days before closing to accommodate salvage efforts to relocate the Dali.

How Is Road Traffic Affected?

The Key Bridge first opened to traffic in 1977, spanning the Patapsco River connecting Interstate 695 on the southeastern side of Baltimore (see Figure 2). It had annual average daily traffic of over 30,000 vehicles in 2023, including over 3,000 trucks per day. It was less heavily used than the Fort McHenry and Baltimore Harbor Tunnels running under the Patapsco River farther north.

Highway traffic has been rerouted through the Baltimore Harbor or Fort McHenry Tunnels or on Interstate 695 to the north of Baltimore City. Some larger vehicles, including all double-trailers, and most shipments of hazardous materials are not permitted in the tunnels, and trucks are not allowed through the Baltimore Harbor Tunnel.

Figure 2. Map of Baltimore Transportation Facilities

Source: Created by CRS using data from the U.S. Census Bureau and ESRI. Notes: The Fort McHenry and Baltimore Harbor Tunnels are marked in brown, and the location of the Key Bridge is marked in red. The Key Bridge location forms part of the southeastern edge of Interstate 695.

Has Anything Like This Happened Before?

Other bridges have collapsed, including as a result of vessel strikes, leading to disruptions in maritime and highway transportation.

In May 1980, the bulk freighter MV Summit Venture struck a support column of the Sunshine Skyway Bridge near Tampa, FL, causing a large portion of the bridge span to collapse and resulting in 35 fatalities. Federal investigators concluded that the probable causes of the collision were the unexpectedly sudden and severe weather, the absence of a severe weather warning, and the failure of the pilot to change course when weather obscured the channel markers.²⁹ The Tampa incident led to the publication of new bridge design guidance for withstanding vessel impacts, but it is not yet known whether the Key Bridge—built before this guidance existed—could have withstood the Dali's impact even if it conformed to current design best practices.

In May 2002, the towboat Robert Y. Love and the two barges it was pushing veered off course and struck a support column of a bridge carrying Interstate 40 over the Arkansas river in Oklahoma, also causing a section of the bridge to collapse and resulting in 14 fatalities. Federal investigators concluded that the probable cause of the incident was the captain's loss of consciousness, possibly as the result of an unforeseeable, abnormal heart rhythm.³⁰ The inability of motorists to detect the collapsed bridge in time to stop their vehicles contributed to the loss of life.

Who Is in Charge of the Safety Investigation?

The U.S. Coast Guard shares responsibilities with the NTSB to investigate major safety incidents. Under the NTSB's governing statutes³¹ and regulations,³² the agency shall investigate any "major marine casualty," defined as one that results in the loss of six or more lives, the loss of a vessel larger than 100 gross tons, property damage initially estimated as at least $0.5 million, or a release of hazardous materials deemed to be a serious threat.³³ The U.S. Coast Guard is directed to conduct a preliminary investigation to determine whether a major marine casualty event has occurred and notify the NTSB accordingly. The NTSB has stated that it will take 12 to 24 months to fully investigate this incident and has released an initial timeline of the incident.³⁴

What Is the Federal Government's Role in Rebuilding the Bridge?

Rebuilding the Key Bridge would require permits from federal agencies, and these authorizations would normally require review under the National Environmental Policy Act (NEPA). However, replacement of a damaged or destroyed bridge may be granted a "categorical exclusion" (CE) exempting it from further NEPA reviews if certain conditions are met. To qualify for a CE, work must begin within two years of an emergency declaration and occur "within the existing right-of-way and in a manner that substantially conforms to the preexisting design, function, and location as the original (which may include upgrades to meet existing codes and standards as well as upgrades warranted to address conditions that have changed since the original construction)."³⁵

After the Interstate 35W bridge in Minneapolis collapsed in 2007, a new bridge was completed in 11 months, which was 3 months ahead of schedule. The Federal Highway Administration (FHWA) credits a project scope that qualified for a CE with accelerating project delivery. In Florida, a new Sunshine Skyway Bridge took five years to complete, but traffic was able to resume at reduced capacity on a parallel span that did not collapse.

Federal funding may be available to replace the bridge, which state officials have estimated may take approximately four years at a cost of between $1.7 and $1.9 billion.³⁶ FHWA's Emergency Relief (ER) Program receives approximately $100 million per year from the Highway Trust Fund. Congress has periodically provided additional funds to respond to specific incidents. Any damages or insurance payouts recouped by a bridge owner would be used to offset any ER funds awarded. Before submitting a standard ER application, state transportation officials can submit a streamlined application for "Quick Release" funds to cover emergency operations; the State of Maryland has applied for and received $60 million in such funds for the Key Bridge collapse.

Under the ER Program, federal funds can cover 90% of project costs for interstate highways and 80% for other federal-aid highways. Although the Key Bridge is a segment of Interstate 695, the portion that includes the bridge is a state highway, so the maximum federal share could be 80%. However, if the total expenses Maryland incurs to deal with disaster-damaged roads in FY2024 exceed the state's total federal-aid highway formula funds ($828,287,771 for FY2024), the maximum federal share could increase to 90%. In the past, Congress has made exceptions allowing ER funds to cover 100% of costs for specific projects, as it did for the Interstate 35W bridge project (see P.L. 110-56). A bill introduced in the Senate, S. 4114, would make all costs related to the repair and reconstruction of the Key Bridge and its approaches eligible for a 100% federal share.

Will Baltimore Want a Higher Bridge Like Those at Other Ports?

In addition to dredging deeper channels to allow for larger ships, some ports have had to build new bridges with higher clearances to allow ships to pass under. The ports of Long Beach and New York are examples of harbors where either a bridge was entirely replaced or the deck of the existing bridge was raised to accommodate taller vessels. Savannah, GA, plans to raise the deck of the Talmadge Memorial Bridge another 20 feet in 2025. As shown in Table 1, the Francis Scott Key Bridge in Baltimore had a relatively high clearance relative to bridges in other seaports. Also, the Chesapeake Bay Bridge, which most ships calling at Baltimore would also need to pass under (those ships sailing up the Chesapeake Bay), has an air draft that is three feet less than that of the Key Bridge.

Though a higher bridge may not be sought in this case, the issue points to the higher costs that larger ships impose on the public. While larger ships increase economies of scale at sea, they impose higher port costs largely borne by the public and not the shipping lines. This includes the cost of deeper channels, taller bridges, and higher capacity ship-to-shore cranes and other cargo handling equipment, as well as greater concentration of cargo flow, which accentuates port-area congestion.

What Is the Coast Guard's Role in Bridge Permitting?

Bridges to be built over navigable waterways must submit their design plans to the Coast Guard so that the agency can ensure the bridge does not impose a safety hazard for navigators.³⁷ The Coast Guard and the FHWA have signed a memorandum of agreement that is intended to expedite and coordinate their roles in bridge permitting.³⁸ In addition to reviewing new bridge design plans, the Coast Guard's Office of Bridge Programs funds alterations to the support structure of bridges found to interfere with navigation and regulates the operation of drawbridges to accommodate the needs of bridge users and navigators.³⁹

Could the Owner of the Dali Be Liable for Damages?

On April 1, 2024, the Dali's owner filed a petition in federal district court under the Limitation of Liability Act of 1851, 46 U.S.C. §§30521–30530, asking the court either to exonerate the owner from liability for the collision or to restrict the owner's potential financial liability to approximately $43 million. This figure, known as an "interim stipulation of value," is related to the value of the vessel itself and the amount earned from the vessel's voyage. Shipowners filed similar petitions following the Sunshine Skyway and Interstate 40 bridge collapses but voluntarily settled with various claimants for amounts that exceeded their interim stipulations of value. For more information about how courts evaluate such petitions, see CRS Legal Sidebar LSB11155, The Baltimore Bridge Collapse and the Limitation of Liability Act of 1851, by Bryan L. Adkins, Alexander H. Pepper, and Clay Wild.