The day after the April 20, 2010, explosion on the Deepwater Horizon drilling rig in the Gulf of Mexico, Brent Coon & Associates got involved in what has become massive tort litigation.

Brent Coon says his firm began working on cases stemming from the explosion and subsequent oil spill when an injured oil rig worker asked to be represented by an attorney at Coon & Associates. On behalf of Stephen Stone and his wife, the firm filed Stone, et al. v. Transocean Offshore Deepwater Drilling Inc., et al. in a state district court in Harris County. The defendants removed Stone to federal court, and the case wound up in the multidistrict litigation in the U.S. District Court for the Eastern District of Louisiana.

"It has languished there ever since," Coon says.

Since filing Stone, the firm has amassed a docket of almost 15,000 individual claimants, Coon says. Of that number, he says, less than 25 percent have been settled.

Eric Newell, an attorney whom Coon identifies as his "right hand man," estimates that to date, the firm has collected gross settlements totaling about $50 million, including less than $10 million in attorney fees.

But Coon says his firm has spent between $10 million and $20 million on the cases, including more than $5 million on forensic accounting costs.

The firm also tripled its staff in order to handle all the claims, growing from about 10 people to more than 30, Newell says. While only three of the firm's approximately one dozen lawyers handle day-to-day matters for the oil spill cases, all of the lawyers get involved at times, he says.

"It's been all hands on deck three or four times," Newell says.

Coon says victims could follow either one of two different tracks: settling with BP PLC or pursuing traditional litigation. He says that neither track has offered an acceptable solution for most of his firm's clients.

Victims of oil spills are entitled to file claims under the Oilfield Pollution Act (OPA) of 1990, which Congress created to give claimants and the party responsible for an oil spill a way to reach compensation agreements outside the court system. Although BP set up a $20 billion fund to compensate victims of the Gulf of Mexico oil spill, claimants and their lawyers have faced repeated changes in the requirements.

"The rules of engagement have constantly changed like they never have in any other litigation," Coon says.

Coon says his firm first assisted clients in making claims to BP's internal review and payment process and later helped them submit claims to the Gulf Coast Claims Facility (GCCF), which was dismantled in 2012. Now there is a court-supervised settlement program, which Coon has criticized.

Paul Danziger, a partner in Houston's Danziger & De Llano, has worked with Coon on hundreds of the Deepwater Horizon cases and says Coon really cares about the working class people harmed by the oil spill.

"He was one of the few lawyers who let it be known this (the settlement) was not a good deal for his clients, and he was right," Danziger says.

Coon & Associates has obtained compensation for some of its clients, however. Newell says the firm has "done a good job" of resolving claims for its fishing boat clients.

"Out of a little less than 100 shrimp boat cases, we have less than 10 left," he says.

But Newell says the firm has resolved less than a dozen of several thousand claims it has for individuals.

Newell says some of the firm's clients accepted GCCF offers, but collecting on those offers has not been easy. Newell says one casino worker represented by Coon & Associates accepted a GCCF offer in March 2012, received 60 percent of the money in late 2012 but did not receive the final 40 percent until June.

In April, on the eve of the three-year filing deadline established pursuant to the OPA, Coon & Associates filed multiple suits against BP and other defendants in several jurisdictions along the Gulf Coast on behalf of more than 10,000 clients who claim to be victims of the oil rig explosion and ensuing oil spill.

Danziger says Coon is handling about 800 of Danziger & De Llano's cases that are outside the settlement and must be tried.

"He's the guy we would want to associate with on our cases if they're going to trial," Danziger says.