BP Westlake Campus, Texas

BP, formerly known as British Petroleum, has its largest American presence in an expanding corporate campus on the I-10 Energy Corridor west of Houston. BP is the third largest of the supermajor oil companies (after ExxonMobil and Shell). It is the largest shareholder of the Alaska Pipeline, and operates three refineries in the United States. The company's refining and chemical center in Texas City, is one of the largest petrochemical complexes in the world. An explosion there in 2005, killed 15 workers and injured at least 180 more. In 2010, over 530,000 pounds of toxic chemicals were released into the atmosphere, due to malfunctioning equipment at the facility. Two weeks later, the Deepwater Horizon, an offshore oil drilling rig operated by BP, exploded and sank in the Gulf, resulting in the deaths of 11 workers and what is to date the worst environmental disaster in the U.S.