The cause of the rupture and the total volume of oil released after the North Dakota spill remain unclear, officials said.

The new spill Wednesday at 5.30 am was due to a malfunction in an unloading maneuver in the monobuoy operated by the company Oiltanking, which said in a statement that this time it acted more ...

The Keystone pipeline system, which carries crude oil from Canada to the United States, was shut down on Tuesday morning ...