The cost of litigation resulting from last week's terrorist attacks in the US is likely to be far smaller than originally thought, legal experts say.

Traditionally, the American response to a mass tragedy is a rush to the courthouse. But this time, they say, things are likely to be different. And even those suits which are filed may not succeed.

Congressional action to limit the liability of airlines will mean a big reduction in civil litigation targeting the air carriers. But other potential defendants - those who designed, built and operated the World Trade Center, the airports, and even some Trade Center employers - may also escape litigation altogether, or see suits dismissed in court, according to legal experts.

And for once, America's much maligned plaintiffs' lawyers - who normally benefit hugely from such litigation - say they are solidly behind moves to limit legal claims. They have been vigorously lobbying Congress for a system of compensation which does not involve the courts - a special administrative proceeding which would be quicker than litigation.

"We need to think outside the box on this one," says a spokesman for the Association of Trial Lawyers of America (ATLA), the leading group of plaintiffs' lawyers. "Litigation will be too slow."

Prominent plaintiffs' lawyers said they expected most of their colleagues to observe restraint. "If we sue each other, the terrorists win," says Elizabeth Cabraser, one of America's leading personal injury lawyers. "We need to be united. Litigation is divisive.

"People do have rights, but I can't believe anyone at the airlines or the World Trade Center is anything but devastated. They were used against their will."

Less scrupulous lawyers will no doubt file suits anyway, against the management of the World Trade Center (for allegedly encouraging tenants to return to the tower after the first crash), those who built the building in such a way that it could not withstand attack, perhaps even those who determined the width of the stairwells, and the design of airliner cockpits without heavy security doors.

After the Oklahoma City bombing, for example, families of victims sued the company which manufactured the fertiliser used to make the bomb, arguing that it did not adequately safeguard its product from use by terrorists. They did not, however, succeed.

Success is even less certain this time, the plaintiffs' lawyers acknowledge. "When everybody in this country and most people in the world blame the terrorists, why would a jury say the airlines were responsible?" asks one of them.

Many such suits may never make it to a jury, legal experts say. Though America's judges frequently allow personal injury suits which drag in all peripherally related defendants, this time may be different. They may view many such defendants as victims rather than wrongdoers, and dismiss such suits at the start.