A man identified by police as a security guard shot and killed a striking coal miner in eastern Kentucky yesterday as the impasse in coal contract talks deepened in Washington.

In the first reported death in the month-long strike by the United Mine Workers, Kentucky State Police said Mack Lewis, 65, of Prestonburg, Ky., was shot five times about 9:30 a.m. at a railroad crossing where Lewis and four other miners had set up a picket line.

According to wire service reports, Ralph Anderson, whom State Police Capt. Walter Sims identified as a security guard who worked at the railroad crossing, was arrested at the scene and charged with murder. Anderson was held without bond and ordered removed to the Fayette County Jail at Lexington, Ky., about 90 miles to the west.

"Why it erupted we don't know," said Sims. "They apparently just had words."

There have been numerous indidents of vandalism and violence since the UMW went out on strike Dec. 6, but no other fatalities have been reported.

Meanwhile, in Washington UMW President Arnold Miller sent the union's 14-man bargaining team home in an apparent attempt to build up pressure on the coal operators to resume negotiations.

The Bituminous Coal Operators Association broke off talks a week ago after the UMW rejected a proposal under which striking miners would reimburse health and retirement funds for income lost as a result of wildcat strikes.

The union had previously indicated it would accept the plan, which was viewed as the key to unraveling the tangled work-stability and benefits-guarantee issue, but backed off in apparent concern over an adverse reaction from rank-and-file miners. Any contract must be ratified by a vote of the union's 160,000 working members.

In a statement, Miller charged that the operators were boycott[ing] the bargaining table despite the suffering inflicted upon the 300,000 miners and their families by their failure to return," and added: "I have no alternative but to release the bargaining committee."

The bargaining team could be recalled at any time, however, and there were indications yesterday that the Federal Mediation and Conciliation Service may seek a resumption of the negotiations sometime next week. BCOA had no comment on Miller's statement.

Miller's dispatching of his bargaining team came amid increasing signs that the strike is having even less impact than expected on coal stockpiles and thus the nation's energy supplies for the winter.

Non-struck mines are producing from 40 to 50 per cent of the normal national coal output, and it now appears that pre-strike coal production was so high that the stockpiles are larger than estimated a month ago.

"What appeared to be a 90-day supply for the utilities turns out to be a 100-day supply," one industry official said.

Government and industry officials are now saying it will take another month or more before utilities, steel-makers and other heavy coal users begin to suffer. The Federal Energy Regulatory Commission said utility stocks were sufficient to last 88 days as of Dec. 31, a reduction of 12 per cent from the 100-day supply as of the start of the strike.

The miners are their families doing the suffering, although a patch-work of improvised medical care plans is taking some of the strain out of the total cutoff of health benefits that took effect when the strike started. Pensions were paid this month for the last time until the strike ends, according to UMW funds officials.

Administration sources said yesterday that there are still no plans to seek an injunction under the Taft-Hartley Act to get the miners back to work.