U.S. Court of Appeals for the Ninth Circuit. Photo: Jason Doiy/ALM

A federal appeals court in California ruled Wednesday that the families of two defense contractors killed in a 2015 terrorist attack in Jordan cannot sue Twitter for allegedly enabling terror group ISIS.

A three-judge panel of the U.S. Court of Appeals for the Ninth Circuit affirmed a ruling by U.S. District Judge William Orrick of the Northern District of California, who said Twitter was not complicit in the Nov. 9, 2015, shooting deaths of the contractors, Lloyd Fields Jr. and Damon Creach.

Ninth Circuit Judge Milan Smith, joined by fellow Circuit Judge Sandra Ikuta and U.S. District Judge Steven McAuliffe of the District of New Hampshire, sitting by designation, affirmed a decision by Orrick, sitting in San Francisco, to dismiss the case.