A Small Town Copes With Tragedy : THE SWEET HEREAFTER, <i> By Russell Banks (HarperCollins: $19.95; 272 pp.)</i>

Russell Banks has used a small town’s response to tragedy to write a novel of compelling moral suspense.

On a snowy morning, the school bus serving Sam Dent, a community at the edge of the Adirondack Mountains, skids off the highway, tumbles down an incline and plunges into the water of an abandoned quarry. Ten children die; others are severely injured. The driver, Dolores Driscoll--a sturdy, compassionate woman who drives to support herself and her crippled husband--had swerved to avoid the sudden appearance of what may have been a child, a small animal or even a snow-fogged trick of vision.

“A town needs its children,” says Dolores, who survives. That is part of the theme of Banks’ superb book, “The Sweet Hereafter.” The main part goes deeper. Communities form to contain and manage the larger kinds of catastrophe. Unmanageable catastrophe can kill or cripple them. Sam Dent survives, but some of its belief in itself is torn away.

Banks relates the erratic lines of destruction, the unpredictable shifts and displacements of the shock wave that radiates from the tragedy. He uses four voices. They belong to Dolores; to Billy Ansel, a widower garage-owner whose two daughters perish; to Nichole, a bright and popular teen-ager who is permanently paralyzed with a broken back, and to Mitchell Stevens, a New York City negligence lawyer who speeds north and camps for months in Sam Dent’s only motel.

He is prompt as Nemesis, this raging, sharp-tongued zealot. Sam Dent is numb with shock; its instinct is to huddle together, to console, to bow its head and move on. Mitchell won’t allow it; somebody must pay.

“There are no accidents” is his creed. This termagant, who boasts that negligence lawyers are “the proctologists of the profession,” makes money, but he also has a cause. The institutions of our society--government and business--operate a cold balance of risk, a calculation that sets the certain cost of better brakes or stronger guard-rails against the possible cost of being sued. Mitchell’s mission, he asserts, is “to make it cheaper to build the bus with that extra bolt.”

He is not after Dolores; on the contrary. She is a gutsy, admired member of the community; she is known for devotion to her charges and for her scrupulous driving and maintenance of the bus. And, of course, she has no money. Nobody questions--at this point--her estimate that she was traveling at a safe speed. And Billy Ansel, numb with loss, backs her up. That morning, he had followed his usual routine of driving into town behind the bus, after putting his daughters on board.

Dolores, then, in her anguish, is another victim; and Mitchell tries but fails to add her to his list of parents willing to sue the sueable: the town, county and state. It is a shorter list than he had expected. Mitchell may be after justice, but it is a destructive, rending justice. Banks’ moral questions battle each other with the savagery and flair of a bullfight. The town, after all, is the town. To the bereaved, it is both them and us .

Among those who sign up are the parents of Nichole, whose bright prospects will forever be bound to a wheelchair. Dolores’ refusal remains passive; the two principal opponents to Mitchell and his lawsuits are Billy--and Nichole herself.

Billy is aghast at what is happening to his community. People have gone suit-crazy, he rages. Lawyers are suing each other for stealing clients. The school authorities are being sued for their choice of how to spend the contributions that flood in. There is talk of suing the rescue squad for failing to save more children.

Nichole’s motives are more complex. She is idealistic and she is angry. Why should she, who is only crippled, make money off a tragedy that has killed her friends? But there is a darker story. Her father is a mild man who had sexually abused her for years.

Realizing she has the power to wreck his case and his expectations of money, Nichole does so. It is a startling and moving act, not only reprisal but liberation as well. From her seat behind Dolores, she had had a clear view of the speedometer. And, she testifies in a pretrial deposition, it showed the bus traveling at 20 m.p.h. over the speed limit. The lawsuits promptly collapsed. Mitchell retreats to New York, and Nichole, who lets her father know just what she has on him, has won freedom. Compared to abuse, a wheelchair confines far more lightly.

If this were all, Banks would have written a remarkable book, a sardonic and compassionate account of a community and its people, and of a catastrophe that vividly characterizes them even as it brutally acts upon them. His portrait of the small northern town is complex and spare at the same time; every detail stands out. None of the principal characters is simple. Mitchell is a second catastrophe following the first; yet his argument is lucid and compelling. Nichole is arrogant as well as innocent, and her act of liberation has an awful ambiguity to it. Billy, more human and less specifically focused, is a mixture of saintliness and weakness.

If this were all--but it’s not. What about Dolores? Nichole’s testimony seems to expose her, not as wicked but as pitiable. And this creates a disquieting puzzlement. Surely, she is the same person who in her first narrative, which opens the book, seemed so warm, so observant, so shrewd and, in a rough-hewn way, so strong. All these qualities suddenly feel contaminated.

In her second narrative, which comes at the end, our disquiet is dispelled--not smoothly but with powerful tension--and our admiration flowers. For her--and I can’t say more without revealing the story’s crucial puzzle--and for Banks. He has told us the real story all along while, without the least trickery, mananging to conceal it. He also has written an extraordinary fictional character and revealed her to us in a fashion that is theater as much as fiction.

Dolores, finally, will serve as scapegoat. Mitchell was right, in a way; the town needed one. Instead of suing--and, in a way, blaming themselves--the Sam Denters are able to turn their anguish onto a single person. When she goes, one by one, to the funerals of the dead children, no one speaks to her and she respects the silence, even while suffering from it.

Her discourse emerges as the bitten-off, self-taught poetic current that makes “The Sweet Hereafter” much more than the sum of its excellent parts. Stoic and perceptive, capable of a beautifully colored phrase side-by-side with a resigned commonplace, Dolores ends as an exile to everything but her valiant and expanding spirit. There are one or two rough passages, but Banks, one of our strongest writers, has touched his unglamorous small-town Americans with light, and written, I think, his best book.