Two men trapped in a West Virginia coal mine made a "valiant effort" to escape, but were blocked by scorching heat and thick smoke from a conveyor belt fire that also prevented rescuers from finding their bodies for two days, the director of the state mining agency said.

The fatalities rose the state's death toll of miners killed on the job to 14 in less than a month and prompted renewed calls to improve mine safety.

Gov. Joe Manchin said he planned to introduce legislation Monday dealing with rapid responses in emergencies, electronic tracking technology and reserve oxygen stations for underground miners.

"These two men who perished in this mine, the 12 men who perished in the Sago Mine, I can only say to each of those families ... that they have not died in vain," Manchin said. Twelve miners died after a Jan. 2 explosion at the Sago Mine, more than 180 miles away. The sole survivor of that accident remained hospitalized in a light coma.

The latest two victims died in the Aracoma Coal's Alma No. 1 mine in Melville, about 60 miles southwest of Charleston. A conveyor belt caught fire Thursday and the two victims — both husbands and fathers with more than a decade of mining experience — became separated from their 12-member crew.

The rest of the crew and nine other miners working in another section of the mine escaped unharmed.

The bodies were found Saturday in an area of the mine where rescue teams had been battling the intense blaze for more than 40 hours. Rescuers could not enter that portion of the mine until the flames had been mostly extinguished and the tunnels cooled down.

It appeared the two victims, identified as Don I. Bragg, 33, and Ellery Hatfield, 47, made a "valiant effort" to escape, said Doug Conaway, director of the state Office of Miners' Health Training and Safety.

The bodies were to be sent to a medical examiner's office in Charleston.

Rescue efforts were also hampered by intense heat and smoke that cut visibility to 2 to 3 feet in some parts of the mine. Teams were able to get into four tunnels, each about four miles long, but they could not get beyond the burning conveyor belt. Heat from the fire had also caused the roof of the mine to deteriorate.

The two men had been equipped with oxygen canisters that typically produce about an hour's worth of air.

Jimmy Marcum, a 54-year-old retired miner from Delbarton, said better equipment is needed to protect miners.

"I mean, they can send a man to the moon but they can't make a (oxygen canister) that will last at least 16 hours," Marcum said. "That's what they need to do."

Manchin planned to travel Tuesday to Washington to discuss his proposals with the state's congressional delegation, hoping they will seek reforms on the federal level.

Rep. Nick Rahall (news, bio, voting record), D-W.Va., said Congress must give the federal Mine Safety and Health Administration the tools to operate effectively, and may have to increase its budget.

"It's unfortunate that every coal mine health and safety law on the books is written with the blood of coal miners," Rahall said.

The federal Mine Health and Safety Act was written a year after a 1968 explosion in Farmington that killed 78 miners, including Manchin's uncle.

Massey Energy opened the mine in 1999, and these are its first fatalities. The company said in a statement it was saddened by the miners' deaths and would focus on comforting the families.