-- March 23, 2005: Explosion kills 15 people and injures more than 170 in the worst accident in the nation's gas and chemical industry in almost 15 years. The explosion sends flames and smoke billowing into the sky and rattles homes as far as five miles away.

-- May 17, 2005: Company executives, in an interim report, say errors by workers and supervisors led to the explosion and fire. "The mistakes made during the startup of this unit were surprising and deeply disturbing," said Ross Pillari, president of BP Products North America.

-- June 28, 2005: Federal investigators say key pieces of instrumentation and alarms at the refinery weren't working properly. Don Holmstrom, lead investigator with U.S. Chemical Safety and Hazard Investigation Board, said an alarm within the isomerization unit -- a device that boosts the octane in gasoline -- didn't work properly until after the explosions had begun.

-- Aug. 17, 2005: The U.S. Chemical Safety and Hazard Investigation Board, known as the CSB, issues an urgent safety recommendation for the first time in its history, requesting BP PLC form an independent panel of experts to review safety at the company's five North American refineries.

-- Sept. 22, 2005: BP Products North America Inc., the owner of the Texas City refinery, was fined more than $21 million, a record for the Occupational Safety and Health Administration agency, which oversees workplace safety.

-- Oct. 24, 2005: BP announces former Secretary of State James A. Baker III will head an independent panel investigating safety and management oversight at BP Products North America.

-- Oct. 27, 2005: Federal investigators say the plant fostered a culture of bad management and a failure to recognize and correct problems at the facility. The CSB says its preliminary review shows the isomerization unit should not have been started up because of a history of problems and malfunctions.

-- Nov. 23, 2005: The company releases a survey that shows Texas City BP workers felt the refinery's top priority was making money and that managers neglected safety in the months before the explosion. BP released the survey and an audit after attempting to keep the documents and thousands of others from public disclosure.

-- Dec. 9, 2005: BP blames management system failures for the explosion. BP says will it invest about $1 billion over five years to improve and maintain the site. The company says its investigation team "found no evidence of anyone consciously or intentionally taking actions or decisions that put others at risk."

-- Sept. 13, 2006: The family of an engineer killed in the explosion settles a lawsuit with BP, a week before jury selection in the trial. That settled all suits by relatives of the 15 killed except the one brought by the family of killed employees James and Linda Rowe.

-- Oct. 31, 2006: An investigative board urged the petroleum industry and federal regulators to eliminate from all U.S. refineries the type of atmospheric vent that caused the Texas City blast.

-- Nov. 9, 2006: BP settles the last remaining death-related lawsuit from the explosion. Eva Rowe, 22, received an undisclosed amount in a settlement that also called for BP to continue to release documents related to the case and to donate millions to schools and medical facilities.

-- Jan. 16, 2007: An independent study by the Baker panel says BP failed to emphasize safety at its U.S. refineries before the Texas City explosion.

-- March 20, 2007: The CSB issues its final report, criticizing OSHA for lax oversight at the plant while reiterating claims that organizational and safety deficiencies at all levels of BP led to the blast. The agency recommends, among other things, that BP appoint an additional board member with expertise in process safety and for BP senior executives to establish an improved incident-reporting program and use new indicators to measure safety performance.

-- Sept. 5, 2007: Four workers injured in the blast become the first plantiffs whose case goes to trial. It was the only lawsuit stemming from the blast to reach the courtroom.

-- Sept. 18, 2007: The first trial ends in undisclosed settlements with the workers.