The 49-page ruling issued Tuesday stems from suits filed by 70 of those injured and representatives of those who died in the terrorist attacks.
The defendants argued the suits should be dismissed because they had no duty to anticipate and guard against deliberate and suicidal aircraft crashes and because any alleged negligence on their part was not the cause of the deaths and injuries.
U.S. District Judge Alvin Hellerstein ruled, however, the Port Authority of New York and New Jersey, which owns the World Trade Center property, "has not shown that it will prove its defense of governmental immunity as to negligence allegations made by WTC occupants."
The complaints also alleged Boeing should have designed its cockpit door to prevent hijackers from invading the cockpit.
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