American Airlines and United Airlines lost their argument before a federal judge who ruled they must face trial over negligence claims related to the September 11, 2001, hijackings.

The airlines were sued by the owner of the World Trade Center, which has argued that American and United were negligent for allowing terrorists to board and hijack the planes that were flown into the buildings. American Airlines Flight 11 crashed into the North Tower of the World Trade Center and United Airlines Flight 175 crashed into the South Tower.

Lawyers for the defendants said that because World Trade Center Properties LLC had already collected $4.1 billion from insurance companies, the plaintiff could not force the airlines to pay as well.

Judge Alvin Hellerstein disagreed and ordered the case to proceed to trial. World Trade Center Properties sought an additional $8.4 billion in damages, which included the estimated cost of replacing the two towers that were destroyed, but Hellenstein capped their potential gain at $2.8 billion, the value of its lease of the property from the Port Authority of New York and New Jersey.

-Noel Brinkerhoff, David Wallechinsky

To Learn More:

American, United Airlines Must Face Trial Over 9/11 Attacks (by Patricia Hurtado, Bloomberg News)

World Trade Center Properties v. United Airlines (U.S. District Court, Southern New York)

Cantor Fitzgerald Asks Court Permission to Activate Lawsuit against American Airlines over 9/11 Deaths (by Matt Bewig and David Wallechinsky, AllGov)

Family Forced to Settle 9/11 Lawsuit against United Airlines Out-of-Court (by Noel Brinkerhoff and David Wallechinsky, AllGov)

Airlines and Airport Security Agree to Pay $1.2 Billion for 9/11 Property Damages (by Noel Brinkerhoff, AllGov)