At a time when steel mills in the U.S. are running flat out to meet increasing demand, the steel industry is trying to unravel the causes of on-the-job accidents that resulted in more deaths in the first half of 2008 than in recent full years.

The increase in fatalities has prompted the world's largest steel maker by revenue and output, ArcelorMittal (owner of the former Georgetown Steel some 50 miles up the coast from Charleston), to agree to tie more executives' compensation to plant safety performance and to establish joint health and safety committees in all of its facilities under an agreement with unions. ArcelorMittal has had four fatalities involving workers at four different plants in the U.S. this year.

Union officials and steel-company executives say 15 U.S. workers died in the first half in steel-mill accidents that included falls, an explosion and a number of cases in which workers were crushed by huge pieces of steel or equipment. In all of 2006, the latest full year for which government statistics are available, 14 workers were killed at iron and steel mills, an industry category tracked by the Labor Department.

The number of fatalities has risen from eight in 2005, nine in 2004 and eight in 2003, according to the U.S. data. Employment in the industry has remained steady over the past year at roughly 100,000 workers, but overtime has risen about 20 percent this year, the department says.

Officials at the United Steelworkers, which is negotiating labor contracts with U.S. Steel Corp. and ArcelorMittal, contend that pressure to boost steel output while the market is strong has led to some fatalities and that recent industry consolidation and ownership changes may have diverted attention and resources away from safety at some companies.

Steel executives say they don't believe higher production has compromised safety, or that their focus on safety has diminished. But they are at a loss to explain any specific reason for the rising number of worker deaths and are re-evaluating their safety practices to try to prevent more.

"Unfortunately, our company and our industry are missing that mark and, as a result, 15 people have died this year," John Surma, chief executive of Pittsburgh-based U.S. Steel, said in remarks before a group of steel executives in June. "There was no pattern of age or experience, poor health or drug use or exposure to a common unsafe condition that figured in the fatalities."

Surma added that "the only thing that was true in every case was that something went horribly wrong." In the case of a U.S. Steel mill outside Detroit, a worker was killed in January as the result of a gas-pipeline explosion.

Working amid molten steel and large machinery has never been accident-free. Nor does the steel industry rank as dangerous as the construction industry, for example, which had 1,239 fatalities in 2006, or a rate of 10.9 per 100,000 workers, according to government statistics. But the sudden rise in steel-workplace fatalities stands out and comes amid a decline in the steel industry's accidents of all types.

"There is more overtime, maintenance being deferred and cutbacks in company safety efforts," said Michael Wright, director of health, safety and environment for the United Steelworkers. Amid rapid consolidation of steel companies, "A lot of the (safety) personnel and the programs just disappeared," he said.

Steel executives adamantly deny that safety is being sacrificed for profits. "We have a zero-tolerance policy" for safety violations, said Keith Busse, CEO at Steel Dynamics Inc., a midsize steel company based in Fort Wayne, Ind. Busse also is board chairman of the American Iron and Steel Association.

This year's fatalities have occurred at big and small producers. Two workers were killed in different accidents at the same Gerdau Ameristeel Corp. mill in Jackson, Tenn. Mario Longhi, Gerdau Ameristeel's president and CEO, said that after each of these incidents, the company reiterated its safety procedures to employees.

In the case of a man who was crushed by a crane on March 24, Longhi said that the worker had been instructed on safety procedures implemented a year earlier that required the overhead crane to come to a complete stop before another worker - in this case, the victim - ascended the crane to begin his shift as operator. The man, a relatively new employee, didn't wait for the crane to stop and was crushed as he attempted to climb aboard.

In recent years, the steel industry has implemented safety improvements such as better protective clothing to protect workers from furnaces and reduce heat-related injuries, and improved harnesses for crane operators. In 2004, three steel-industry associations worked with the Labor Department's Occupational Safety and Health Administration to cut the number of injuries and fatalities. OSHA targeted the industry because of its high injury rate.

The three-year alliance ended in 2007, after a reduction in the injury rate across the industry, but also as the industry was ramping up production to both meet strong demand in the U.S. and take advantage of high prices.

Thomas Danjczek, president of the Steel Manufacturers Association, which represents 70 percent of the U.S. steel industry, said companies "have spent an awful lot of time trying to look for common or like reasons that have driven" the increase in worker deaths, but none have emerged. He said his group is working on a fatality prevention plan, targeting five areas, including cranes and worker falls, which have proved most hazardous.