NEW YORK -- Opening the door to scores of Sept. 11 lawsuits against the aviation industry, a judge concluded Tuesday that the hijacking and crashing of a jetliner was a "foreseeable risk."

U.S. District Judge Alvin Hellerstein said negligent security screening might have contributed to the deaths of 3,000 people in the attacks on the World Trade Center and the Pentagon and the crash of a hijacked plane in Pennsylvania.

"The aviation defendants controlled who came onto the planes and what was carried aboard. They had the obligation to take reasonable care in screening," he wrote.

The decision involved the cases of about 70 people injured or killed in the attacks.

The defendants -- American and United Airlines, the Boeing Co. and the Port Authority of New York and New Jersey -- had sought dismissal of the lawsuits, saying they had no duty to anticipate and guard against deliberate, suicidal aircraft crashes and that any alleged negligence on their part did not cause deaths and injuries.

In his ruling, Hellerstein said that while it may be true that terrorists had never deliberately flown airplanes into buildings, "airlines reasonably could foresee that crashes causing death and destruction on the ground were a hazard that would arise should hijackers take control of a plane."

"The intrusion by terrorists into the cockpit, coupled with the volatility of a hijacking situation, creates a foreseeable risk that hijacked airplanes might crash, jeopardizing innocent lives on the ground as well as in the airplane," he added.

As for the Port Authority, which owns the World Trade Center property, the judge said it "has not shown that it will prove its defense of governmental immunity." He said the plaintiffs have a right to argue the Port Authority did not provide a "safe environment."

The Port Authority also operates Newark International Airport in New Jersey, the departure point for United Flight 93, the San Francisco-bound jetliner that crashed in Shanksville, Pa., on Sept. 11, 2001.

Litigation or payouts

As a result of the ruling, court officials were preparing for a possible rush of lawsuits as early as this week as some people choose litigation over the federal victims compensation fund. To receive a payout from the fund, families must agree not to sue airlines or other entities.

American Airlines spokesman Todd Burke said the airline would appeal. "We continue to believe that we are not liable for the events that occurred that day," he said.

Port Authority spokesman Steve Coleman said the agency strongly believes "the responsibility rests with the murderers who led the attacks."

Boeing spokesman Ken Mercer said the jet manufacturer would also appeal. "Terrorism, not negligence, is the issue at hand here, and Boeing has always been committed to working with airlines, airports and other officials to make the global air transportation system as safe and secure as possible," he said.

A United representative did not immediately return calls.

"They are important findings, but they are preliminary," said Marc Moller, an attorney for several hundred victims and their relatives. The judge "has not said that the airlines are liable. He said that if the plaintiffs can prove their case, the airlines could be liable. The litigation risks lie ahead, and they are great."

Keith S. Franz, a Baltimore attorney representing seven family members of those killed at the Pentagon and two who were severely injured, said the ruling would probably lead some people to decide to sue.

"From a historical perspective, the amounts individuals receive in airline crash litigation will make the amounts being received by the fund pale by comparison," he said.

Many of the victims and family members of those who died "have never made money an issue," he said. "They want to know what happened and why -- and it's only through litigation that you get to ask those questions," Franz said.

Dec. 22 is the last day families may apply to the federal victims compensation fund, created by Congress to provide aid to the families of those killed or injured in the attacks, and to protect the aviation industry from crippling litigation.

About 2,275 compensation fund claims have been filed. Roughly 1,700 eligible families have yet to decide whether to enroll with the fund or file a lawsuit.

The average fund payout thus far has been about $1.5 million, with the highest award $6.8 million. The minimum payout is $250,000.