MONTCOAL, W.Va. (AP) — A huge underground explosion blamed on methane gas killed 25 miners in the worst U.S. coal mining disaster since 1984, and rescuers on Tuesday began a dangerous and possibly futile attempt to rescue four others still missing.

Crews were bulldozing an access road so they could drill 1,000 feet into the earth to release gases and make it safe to try to find the missing miners.

They were feared dead after the Monday afternoon blast at a mine with a history of violations for not properly ventilating highly combustible methane.

Rescuers were being held back by poison gases that accumulated near the blast site, about 1.5 miles from the entrance to Massey Energy Co.’s sprawling Upper Big Branch mine.

They had to create an access road above it before they could begin drilling four shafts to release methane and carbon monoxide. Gov. Joe Manchin said at a news briefing Tuesday that it could be Wednesday night before the first hole is drilled, but rescuers had to try.

“I don’t want to give anybody any false hope, but by golly if I’m on that side of the table and that’s my father or my brother or my uncle or my cousins, I’m going to have hope,” he said.

It had already been a long day for grieving relatives, some angry because they learned their loved ones were among the dead from government officials, not from Massey Energy executives.

“They’re supposed to be a big company,” said Michelle McKinney, who found out from a local official at a nearby school that her 62-year-old father, Benny R. Willingham, died in the blast.

He was due to retire in five weeks after 30 years mining, 17 with Massey. “These guys, they took a chance every day to work and make them big. And they couldn’t even call us.”

Manchin said a Massey official apologized to family members Tuesday morning in response to complaints that they were not notified of the deaths.

U.S. Rep. Nick Rahall, D-W.Va., who talked with a widow of a miner who had not heard from the company Monday evening, took a harsher stance at a press briefing.

“I think it’s overdue,” he said. “I think this contact is needed.”

Three members of the same family were among the dead. Diana Davis said her husband,

Timmy Davis, 51, died in the explosion along with his nephews, Josh Napper, 27, and Cory Davis, 20.

The elder Davis’ son, Timmy Davis Jr., said his brother, Cody Davis, and an uncle, Tommy Davis, survived the blast.

His brother was taking it particularly hard because he and their father were best friends.

Timmy Davis Jr. described his dad as passionate about the outdoors and the mines.

“He loved to work underground,” the younger Davis said. “He loved that place.”

President Barack Obama offered his condolences at an Easter prayer breakfast in Washington on Tuesday and said the federal government is ready to assist with whatever the state needs.

He also asked the audience to pray for those still in the mine.

Kevin Stricklin, an administrator for the federal Mine Safety and Health Administration, said the situation looked grim for the missing miners.

“All we have left is hope, and we’re going to continue to do what we can,” he said.

Officials hoped the four were able to reach airtight chambers stocked with food, water and enough oxygen for them to live for four days, but rescue teams checked one of two such chambers nearby and it was empty.

The buildup of gases prevented teams from reaching other chambers.

A total of 31 miners were in the area during a shift change when the explosion rocked the mine, about 30 miles south of Charleston.

“Before you knew it, it was just like your ears stopped up, you couldn’t hear and the next thing you know, it’s just like you’re just right in the middle of a tornado,” miner Steve Smith, who heard the explosion but was able to escape, told ABC’s “Good Morning America.”

Massey Chief Executive Officer Don Blankenship told The Associated Press in an interview Tuesday that a carbon monoxide warning was the first sign of trouble.

Mine crews were checking on the alarm when they discovered an explosion had occurred deep inside the mine.

“I don’t know that we know what happened,” he said.

Some of those killed may have died in the blast and others when they breathed in the gas-filled air, Stricklin said.

Eleven bodies had been recovered and identified, but the other 14 have not. Names weren’t released.

Manchin said investigators still don’t know what ignited the blast, but methane likely played a part.

The death toll is the highest in a U.S. mine since 1984, when 27 died in a fire at Emery Mining Corp.’s mine in Orangeville, Utah.

If the four missing bring the total to 29, it would be the most killed in a U.S. coal mine since a 1970 explosion killed 38 at Finley Coal Co., in Hyden, Ky.

“There’s always danger. There’s so many ways you can get hurt, or your life taken,” said Gary Williams, a miner and pastor of New Life Assembly, a church near the southern West Virginia mine.

Though the situation looked bleak, Manchin said miracles can happen and pointed to the 2006 Sago Mine explosion that killed 12.

Crews found miner Randal McCloy Jr. alive after he was trapped for more than 40 hours in an atmosphere poisoned with carbon monoxide.

In Monday’s blast, nine miners were leaving on a vehicle that takes them in and out of the mine’s long shaft when a crew ahead of them felt a blast of air and went back to investigate, Stricklin said.

They found seven workers dead. Others were hurt or missing.

Massey Energy, a publicly traded company based in Richmond, Va., has 2.2 billion tons of coal reserves in southern West Virginia, eastern Kentucky, southwest Virginia and Tennessee.

It ranks among the nation’s top five coal producers and is among the industry’s most profitable. It has a spotty safety record.

In the past year, federal inspectors fined the company more than $382,000 for repeated serious violations involving its ventilation plan and equipment at Upper Big Branch.