Today's typical college sophomore hadn't even been born when the Exxon Valdez oil tanker struck a reef near Valdez, Alaska, in the pre-dawn hours of March 24, 1989.

Its hull pierced by jagged rock, the ship spilled millions of gallons of crude oil into Prince William Sound, killing hundreds of thousands of seabirds, destroying billions of fish eggs, crippling the salmon fishery, and virtually wiping out the sound's herring.

The disaster seemed to be a clear case of negligence: the ship's captain, Joseph Hazelwood, was legally intoxicated at the time, and had surrendered the wheel to overworked subordinates as it navigated the difficult, shoal-dotted waters of the sound.

But in a tale rivaling the protracted legal wrangling in Bleak House, litigation over the spill continues to drag on, two decades later, and the fishermen, cannery workers, and others whose lives were wrecked have yet to find out how much they may receive in compensation.

Three numbers put the spill and its attendant lawsuits into perspective: 1.6 billion, 20, and 6,000.

The first number—1.6 billion—represents the approximate dollar payout that Exxon Mobil Corp. will make to plaintiffs. Maybe. One third of that amount would come from interest that tolled with the 1994 verdict—but the company is continuing to fight that matter.

The second figure—20—is the percentage of any payout that will be vacuumed up by the more than 80 law firms that have represented the plaintiffs.

The final number—6,000—is the most sobering, marking as it does an estimate of how many of the original litigants have died since the first suits were filed. Some 32,000 plaintiffs remain.

Liability questions focused on the captain, who had previously been disciplined for drinking on the job. A jury found Exxon responsible in 1994, awarding $287 million in compensatory damages (a number that rises to $507 million when other settlements are added in) and $5 billion in punitive damages.

Exxon appealed, arguing, among other things, that the captain's malfeasance could not be imputed to the company and that it had already been punished enough by fines and cleanup costs.

Over the next 13 years, the matter ping-ponged between the U.S. District Court in Alaska and the U.S. Court of Appeals for the Ninth Circuit in San Francisco, which in 2007 cut the punitive award to $2.5 billion.

Still the litigation dragged on, with Exxon and the plaintiffs battling all the way to the U.S. Supreme Court.