CHARLESTON, W.Va. (AP) — The new owners of the West Virginia coal mine where 29 men were killed in an explosion agreed Tuesday to pay a record $210 million to cover fines, compensate victims' grieving families and improve underground safety.

It is the biggest settlement ever reached in a U.S. mine disaster.

Under the deal, Alpha Natural Resources — which acquired the mine's owner, Massey Energy, earlier this year — will not be charged with any crimes in the April 2010 blast at the Upper Big Branch mine as long as the company abides by the settlement, U.S. Attorney Booth Goodwin said. But the agreement does not prevent individual employees from being prosecuted.

"No individuals are off the hook," Goodwin said, adding that federal prosecutors are still investigating.

The U.S. Mine Safety and Health Administration, meanwhile, was expected to brief the victims' families and the media Tuesday on its final report on the cause of the disaster, the nation's deadliest mining accident in 40 years. Federal investigators have blamed the blast on a combination of methane gas, a buildup of explosive coal dust and broken or malfunctioning equipment.

Criminal charges in the disaster have been brought against only one person so far: the mine's security chief at the time of the blast, Hughie Elbert Stover. A federal jury convicted him last month of lying to investigators and trying to destroy mine records. He is awaiting sentencing.

The settlement includes $46.5 million in criminal restitution to the miners' families, $128 million for cutting-edge mine-safety improvements, research and training, and $35 million in penalties for years of safety violations at Upper Big Branch and other mines operated by Massey.

Alpha CEO Kevin Crutchfield said the company cooperated fully with authorities and believes the agreement represents "the best path forward for everyone."

"We're particularly pleased that a substantial portion of the settlement is going towards furthering miner safety, which has always been Alpha's guiding principle," Crutchfield said. "We're mindful that the Justice Department investigation arose from a terrible tragedy which took the lives of 29 miners. Our thoughts will always be with the fallen miners and our sympathies with their families."

The $46.5 million in restitution aims to guarantee that the families of the 29 dead miners and two co-workers who survived the explosion each receive $1.5 million. Eighteen families of deceased miners have filed wrongful-death lawsuits, and eight of those have already settled with Massey. Nine other employees have sued, claiming emotional distress from the tragedy.

Those who accept the payout can still pursue lawsuits, but the $1.5 million would be deducted from any future settlement or jury award.

For the families, the deal is about half of what Massey initially offered. Within a month of the blast, the daughter of one dead miner told The Associated Press that Massey was offering $3 million to each of the families.

One victim's mother was furious that a deal had been struck.

"I have no intentions of settling with these people that have killed my son," said Patty Quarles, whose son Gary Wayne was among the victims. "They need to be put in jail."

Well before the disaster, Massey had a poor safety record and a reputation among its union critics for treating fines as the cost of doing business. From Jan. 1, 2009, until the day of the blast, MSHA cited Upper Big Branch for 645 violations and imposed penalties of more than $1.2 million.

Under Tuesday's settlement, Virginia-based Alpha will invest $48 million in a mine safety research trust and spend an additional $80 million to improve safety at all of its underground mines with the latest technology and equipment. The upgrades include sufficient workers and gear to coat mines with crushed limestone to dilute the coal dust created during mining.

The cutting-edge improvements also include digital sensors that continuously monitor air flow and methane levels; meters to measure coal dust levels; and emergency oxygen equipment, similar to what firefighters rely on, that would give miners an uninterrupted supply of air while trying to escape from an underground accident.

"This in several ways is a revolutionary resolution," Goodwin said. "We wanted it to be something constructive and forward-looking."

The settlement will also fund a West Virginia laboratory capable of testing technology under conditions that would be too dangerous to allow in actual mines.

In addition, Alpha agreed to review all its underground mines and correct any problems within 90 days.

Preliminary reports on the disaster by state and federal investigators have said that poorly maintained cutting machines caused a spark that ignited a small amount of naturally occurring methane and a huge buildup of coal dust. Malfunctioning water sprayers allowed what could have been a small flare-up to become an epic blast that traveled seven miles of underground corridors, doubling back on itself and killing men instantly.

The United Mine Workers union said last month that conditions were so dangerous that Massey executives and managers should be prosecuted for "industrial homicide."

A disappointed and angry Clay Mullins, whose brother Rex died in the mine, said he was frustrated that all the money Alpha will spend under the settlement "basically benefits them and MSHA. It doesn't help the families."

Mullins said he and his family want to see criminal charges brought against executives at Massey, not just against low- and mid-level managers.

"It was an act of murder," he said. "They murdered 29 men, and I'm not satisfied one bit."

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