Jan. 18, 2002: A Canadian Pacific freight train derailed near Minot, N.D. Five tank cars rupture, releasing more than 220,000 gallons of anhydrous ammonia.

March 9, 2004: The National Transportation Safety Board determined the derailment was probably caused by a broken joint bar and faulted the railroad for an ineffective inspection and maintenance program.

March 6, 2006: U.S. District Judge Daniel Hovland in North Dakota regretfully dismissed a class-action lawsuit against the railroad, finding that federal law preempted state laws, yet offer no way for victims of rail accidents to recover damages.

April 24, 2006: Hennepin County District Court Judge Tony Leung issues an order saying state laws were not preempted by federal laws, setting up a conflict between the state and federal courts.

May 16, 2006: The Eighth U.S. Circuit Court of Appeals ruled that a group of Minot derailment lawsuits filed in Minnesota must proceed in federal court.

May 22, 2006: The Eighth U.S. Circuit Court of Appeals bars a federal judge in Minneapolis from sending a derailment lawsuit back to a Hennepin County District Court.

Feb. 2, 2007: Chief U.S. District Judge James Rosenbaum rules like Hovland that federal law preempts state laws. He dismissed the group of 31 lawsuits, saying that Congress created the regulations and that the courts must abide them.

July 10, 2007: As Congress debates how to amend the law, the railroad settles numerous lawsuits. Among them, the North Dakota class-action case, which settles for $7 million.

Aug. 3, 2007: President Bush signs off on a new law that allows lawsuits against railroads if the they violate a federal standard of care, or where the railroads violate their own federally approved safety plans. The law is made retroactive to the Minot derailment.

Jan. 18, 2008: Lawyers will argue before the Eighth Circuit Court of Appeals in St. Louis about whether the new railroad safety law is constitutional.

DAN BROWNING