Metro filed a lawsuit against its Boston-based insurance company recently, claiming that it failed to pay extra expenses and costs in connection with the fatal 2009 Red Line crash that killed nine people.

Metro sued Lexington Insurance Co. last week in U.S. District Court for the Eastern District of Virginia in Alexandria. The transit agency claims Lexington was “turning its back” on Metro and didn’t pay costs it suffered after the crash.

Marie Ali, a spokeswoman for Lexington, said, “We’re declining to comment.”

The Washington Examiner first reported the lawsuit.

The Washington Metropolitan Area Transit Authority said the accident caused the agency to lose “more than six million Metrorail riders from Virginia, Maryland, and the District,” according to the lawsuit. The loss of riders cost Metro $13 million or more, the suit alleges.

Lexington “has failed to pay millions of dollars of covered losses, including business interruption loss, that WMATA suffered as a result of the accident,” the lawsuit states. Metro said in the suit that Lexington has paid the agency about $1.2 million — less than 10 percent of its overall business interruption loss.

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