The Keystone oil pipeline was shut down Tuesday morning after it ruptured in a rural area of North Dakota, halting the flow of crude oil from Canada to refineries in the U.S.

The pipeline's operator, South Bow, reported an estimated release of 3,500 barrels of oil confined to an agricultural field about 60 miles (97 kilometers) southwest of Fargo.

South Bow said in a statement that control center leak detection systems indicated a pressure drop, prompting the shutdown.

"The affected segment has been isolated, and operations and containment resources have been mobilized to site," the company stated, emphasizing the safety of personnel and environmental risk mitigation.

The 2,689-mile (4,327 kilometers) pipeline, which transports crude oil from Alberta, Canada, to Texas, averaged 624,000 barrels per day in 2024, according to Canadian regulators. This makes the pipeline a critical fuel line whose closure can significantly affect fuel prices.

Experts offered differing opinions on the potential impact on gasoline prices. 

Ramanan Krishnamoorti, vice president for energy and innovation at the University of Houston, suggested that prices at the pump, particularly for diesel and jet fuel, could rise within one to two days due to the disruption of a unique heavy crude supply. 

He also noted the potential for higher grocery prices due to increased diesel transportation costs.

However, Patrick De Haan, lead petroleum analyst at GasBuddy, indicated that refineries typically have sufficient crude oil reserves to buffer against immediate impacts, but a prolonged shutdown could become problematic. 

Mark LaCour, editor-in-chief of the Oil and Gas Global Network, echoed this sentiment, stating that major refineries have ample storage to continue gasoline refining for several weeks.

Bill Suess, spill investigation program manager with the North Dakota Department of Environmental Quality, said an employee near Fort Ransom heard a "mechanical bang" and shut down the pipeline within approximately two minutes. 

The explosion caused oil to surface about 300 yards (274 meters) south of a pump station. Emergency personnel responded, and a nearby seasonal stream was blocked off as a precaution. However, no injuries or structural damage were reported.

Keystone Pipeline’s latest rupture isn’t the first time. Constructed in 2010, the 30-inch (0.8-meter) pipeline has experienced past ruptures, including one in Walsh County, North Dakota, a few years ago. 

Meanwhile, the Pipelines and Hazardous Materials Safety Administration (PHMSA) will investigate the cause of the rupture.