Francis Scott Key Bridge collapse
On March 26, 2024, the main spans and the three nearest northeast approach spans of the Francis Scott Key Bridge across the Patapsco River in the Baltimore metropolitan area of Maryland, United States, collapsed after one of the bridge piers was struck by the container ship Dali, which had suffered catastrophic power outages that impaired its control systems. Six members of a maintenance crew working on the roadway were killed, one was rescued from the river, and an inspector was rescued from the remaining structure.
The collapse blocked most shipping to and from the Port of Baltimore for 11 weeks. Maryland Governor Wes Moore called the event a "global crisis" that affected more than 8,000 jobs. The economic impact of the closure of the waterway was estimated at $15 million per day.
Maryland officials have said they plan to replace the bridge by late 2030; initial cost estimates of $1.7 billion to $1.9 billion were later revised to $4.3 billion to $5.2 billion.
Background
The Francis Scott Key Bridge was a steel arch-shaped continuous truss bridge, the second-longest in the United States and third-longest in the world. Opened in 1977, the bridge ran northeast from Hawkins Point, Baltimore, to Sollers Point in Dundalk in Baltimore County, Maryland. Before being damaged, it carried Interstate 695, a beltway around Baltimore; its four lanes were used by some 34,000 vehicles each day, including 3,000 trucks, many of which hauled hazardous materials barred from the two harbor tunnels.The bridge crossed one of the busiest shipping routes in the United States: the lower Patapsco River, which connects the Port of Baltimore to the Chesapeake Bay and the Atlantic Ocean. In 2023, the port handled more than 444,000 passengers and 52.3 million tons of foreign cargo valued at $80 billion. It was the second-largest U.S. port for coal, and had been the leading port for automobiles and light trucks for 13 straight years, handling more than 847,000 vehicles in 2023. It employed 15,000 people and indirectly supported 140,000 others, annually helping to generate $3.3 billion in wages and salaries, $2.6 billion in business revenue, and $400 million in state and local tax revenue.
MV Dali is a container ship registered in Singapore, and at the time of the collision was operated by Synergy Marine Group and owned by Grace Ocean Private Ltd, both based in Singapore. A Neopanamax vessel completed in 2015, Dali has a length of, a beam, and a draft. Danish shipping company Maersk chartered Dali upon its delivery. Once in service, Dali had undergone 27 inspections at ports globally, including two in 2023: one in June in San Antonio, Chile, where a fuel-pressure gauge was repaired, and the second in September by the U.S. Coast Guard in New York, which found no problems.
In March 2024, Dali was crewed by 20 Indian nationals and one Sri Lankan. The ship traveled from Panama to New York, arriving on March 19, then sailed to the Virginia International Gateway in Portsmouth, Virginia. The ship left Virginia on March 22 and the following day arrived in Baltimore, where it underwent engine maintenance. An anonymous source told the Associated Press that an alarm on the ship's refrigerated containers went off while the ship was docked, likely due to an inconsistent power supply.
When the bridge was completed in 1977, the largest container ships could hold 2,000 to 3,000 twenty-foot equivalent unit containers. In the 2000s, the governments of Maryland and Baltimore, which relied on port operations to replace lost manufacturing jobs, seized the opportunity provided by the Panama Canal's expansion: they installed new cranes and dredged the harbor to accommodate the up-to-14,000-TEU vessels that began passing through the canal in 2016. At the time of its collision, Dali was loaded nearly to its 10,000-TEU capacity with 4,700 forty-foot containers.
In 1980, a ship roughly one-third the size of Dali struck and lightly damaged one of the bridge's piers. After the bridge collapsed in 2024, anonymous former agency officials told The Washington Post that the Maryland Transportation Authority did not consider studying the possibility of a collision with a larger ship, and instead spent decades studying how terrorists might attack the bridge after the September 11 attacks or inspecting for structural flaws similar to those that caused the I-35W Mississippi River bridge collapse in 2007. In 2018, the World Association for Waterborne Transport Infrastructure noted that ships frequently hit bridges but rarely destroy them; between 1960 and 2015, thousands of barges and ships collided with U.S. bridges, destroying 18 of them.
Federal regulations require national highway bridges to conform to standards established by the American Association of State Highway and Transportation Officials, but AASHTO did not specify how strong bridges should be to withstand ship collisions until 1994. Federal regulations for bridge protection systems from ship collisions were updated in 1991 after the Sunshine Skyway Bridge collapse in 1980, but existing bridges were exempted by a grandfather clause, and the Francis Scott Key Bridge piers lacked the level of fender system or island barriers required of newer bridges. However, engineering experts debate whether such bridge protection systems could have prevented the collapse given Dalis size. The preliminary National Transportation Safety Board report noted that inspections conducted in March 2021 and May 2023 to National Bridge Inspection Standards found the bridge in satisfactory condition.
Collapse
Dali left the Port of Baltimore at 12:44a.m. EDT on Tuesday, March 26, 2024, bound for Colombo, Sri Lanka. The ship had two local harbor pilots on board. Following standard operating procedure in Baltimore, tugboats that piloted the ship from its berth were released once the ship was in the channel. At 1:24a.m., the ship suffered a "complete blackout" and began to drift out of the shipping channel; a backup generator supported electrical systems but did not provide power to the propulsion system. At 1:27a.m., a mayday call was made from the ship, notifying the Maryland Department of Transportation that the crew had lost propulsion and control of the vessel and that a collision with the bridge was possible.One of the pilots requested that traffic be stopped from crossing the bridge immediately. The ship's lights went out and came on again some moments later, then again went off and returned just before impact as smoke once again began rising from the funnel. At the pilot's request, the MDTA Police dispatch asked officers to stop traffic in both directions at 1:27:53a.m.; outer loop traffic was stopped at the south side after 20 seconds, while inner loop traffic was stopped at the north side by 1:28:58a.m., around the time of the collapse. The Maritime and Port Authority of Singapore reported that the ship dropped anchor before hitting the bridge, as part of its emergency procedures.
At 1:28:45a.m., the ship struck the southwest pier of the central truss arch span, at roughly. AIS data showed the ship traveling at a speed of at 1:25a.m. before departing the channel and slowing to by the time of the collision two minutes later.
Within seconds of the collision, the bridge broke apart in several places, leaving sections protruding from the water and the roadway's approaches cut off. The main span fell onto the ship's bow and a section of it came to rest there. The bridge strike and partial collapse were recorded on video.
Multiple vehicles were on the bridge at the time it collapsed, though initially no one was believed to be inside them. Workers were repairing potholes on the bridge and were in their vehicles on a break at the time of the collapse. A resident living near the bridge recalled being awakened by deep rumbling that shook his residence for several seconds following the collapse, which he said "felt like an earthquake".
Emergency teams began receiving 911 calls at 1:30a.m. The Baltimore Police Department was alerted to the collapse at 1:35a.m. Large rescue and recovery efforts were begun. The Coast Guard deployed boats and a helicopter as part of rescue efforts. Fifty public safety divers in eight teams were dispatched to search for people who fell into the river.
Timeline
This timeline is based mostly on the National Transportation Safety Board's preliminary analysis of events from the ship's voyage data recorder, the Maryland Transportation Authority Police log, and the NTSB's Marine Investigation Report MIR-25-40| Time | Event |
| 00:36 | Dali departs Seagirt Marine Terminal. |
| 01:07 | Dali enters Fort McHenry Channel, and the first tugboat leaves the ship. |
| 01:08 | The second tugboat leaves the ship, and the engines are set to "slow ahead". |
| 01:24:59 | With Dali approximately from the bridge and underway at a heading of 142° at, the ship loses low-voltage power, causing a loss of lights, steering, fuel pumps, cooling pumps, and bow thrusters. |
| 01:25:03 | The voyage data recorder ceases to record ship systems, but continues to record audio. |
| 01:25:08 | The main engine shuts down, but generators 3 and 4 remain operational. |
| 01:25:47 | Dali starts turning to starboard, and the helmsman attempts to turn hard to port, not realizing that the rudder was not operational. |
| 01:25:58 | The ships electrician manually closes the breaker on the transformer that converts high voltage to low voltage, restoring LV power and causing the lights to come back on. VDR parametric data recording resumes 4 seconds later. The flushing pump, which was being used to supply the two running generators with fuel, does not start because it was not set to restart automatically. With the ship, or 2.5 ship lengths, from the Key Bridge, the pilot calls the Association of Maryland Pilots dispatcher and tells them to have the police stop traffic on the bridge. |
| 01:26:10 | The emergency generator turns on, restoring steering power, and the helmsman sets the rudder to port 20°. Dense black smoke begins to pour from Dalis funnel |
| 01:26:18 | The ship reaches its maximum rate of turn away from the bridge, 7.5°/minute. |
| 01:26:38 | The pilot sends a radio call requesting tugboat assistance. |
| 01:26:44 | The pilot association dispatcher informs the Maryland Department of Transportation duty officer of Dalis lack of steering. One tugboat begins heading towards the Dali. |
| 01:27:02 | The pilot orders the port anchor be dropped. |
| 01:27:04 | Generators 3 and 4 begin underperforming due to a lack of fuel. The ship's power management system attempts to start generator 2, but is not able to get it online before the other generators fail. Both high and low voltage circuit breakers open. Only limited lighting, steering, and other equipment powered by the emergency generator remain operational. |
| 01:27:07 | Generator 2 comes online providing high voltage power, but low voltage power is not restored because the circuit breakers remain open. |
| 01:27:23 | The pilot commands hard to port, and the pilot in training makes a distress call over VHF radio. |
| 01:27:36 | The electrician manually closes the breakers, restoring LV power to the lighting, main engine, and additional steering pumps. The main engine, which needed to be restarted manually, remains off. An engineer is sent to manually restart the flushing pump that supplies generators 3 and 4. |
| 01:27:46 | With Dali approximately from the bridge, the pilot commands the bow thruster be set to "full to port". The bow thruster is not operational because its pumps had not been manually restarted. |
| 01:27:53 | The MDTA duty officer dispatches units to shut down the bridge. |
| 01:27:55 | The flushing pump is restarted, but the bridge is informed that crews were unable to release the brake to drop the anchor. |
| 01:28:10 | Dali leaves the Fort McHenry Channel and begins to impact the mud near bridge pier 17. |
| 01:28:21 | An MDTA officer blocks off the north end of the Key Bridge, and tells the duty officer that he would warn the constructions crews once another officer was able to relieve him. |
| 01:28:42 | The anchor brake is manually released, allowing the anchor to be dropped. |
| 01:29:09 | Dali collides with the bridge at. |
| 01:29:22 | Pier 17 collapses, with the main spans and their support piers following a few seconds later. |
| 01:29:27 | MDTA reports collapse of bridge. |
| 01:29:37 | Pilot reports collapse of bridge. |
| 01:29:51 | All vehicular approaches to the bridge reported shut down. |