An appellate court Tuesday upheld a jury’s finding that the Port Authority of New York and New Jersey was more than two-thirds responsible for the 1993 terrorist bombing of the World Trade Center that killed six and injured more than 1,000 people.

The Port Authority’s failure to implement adequate security measures in the face of repeated warnings that the structure’s underground parking garage was vulnerable to an “event of potentially catastrophic magnitude” amounted to negligence, the Appellate Division, 1st Department, held in a unanimous opinion.