Lockheed Martin Corp., the Bethesda-based defense contracting giant, permitted a racially hostile work environment for black employees "to grow in intensity" at its Meridian, Miss., plant until an employee shot 14 workers -- 12 of them black -- there last summer, an Equal Employment Opportunity Commission investigation has found.

The July 8, 2003, shootings by Lockheed worker Doug Williams left six of the victims dead, four of whom were black. Williams killed himself at the scene.

The determination was made in a private letter dated July 6 from the EEOC's Jackson, Miss., office. It was made available by a lawyer for the victims' families, who have filed a civil suit against the company. Lockheed said in a statement that it was not responsible for the shootings, which it called "a senseless tragedy."

The letter, written by EEOC area office Director Benjamin Bradley, said that starting in December 2001, Williams created a racially hostile work environment through "hostile, threatening and demeaning comments" and threats to kill black co-workers. Lockheed's reaction to the threats was inadequate, the letter said, and the racially charged atmosphere grew in intensity until the shootings.

Furthermore, the agency added, Lockheed's "response to this violent and fatal act of hostility toward African American employees has been inadequate in reducing the level of hostility in the workplace. We find that this hostile environment exists as to all African American employees employed at the Meridian, Mississippi, location."

The plant makes aircraft parts.

Following EEOC procedures, Bradley invited Lockheed and the affected families to seek an informal resolution of the matter. If the two sides cannot agree, the case would go to EEOC headquarters in the District, where the five-member commission could vote on whether to sue the company. The EEOC wouldn't comment on the letter yesterday.

In its statement, Lockheed said: "While we disagree with the Jackson EEOC office's determination in these matters, it would be inappropriate for us to comment because of the pending litigation related to the Meridian tragedy."

The statement said the company had been cleared of responsibility by state and federal authorities, including the local sheriff and the Occupational Safety and Health Administration, and "is confident that the same conclusion will be reached by the court."

"Out of respect for the victims, their families, our employees and the judicial system, we will have no further public comment on the litigation or the reported findings of the Jackson EEOC office," the statement said.

Tyrone Means, a Montgomery, Ala., lawyer representing the family of one of the dead workers, Lynette McCall, said yesterday the EEOC letter is "a significant progressive move for this family."

"Nothing will ever bring these persons back," Means said. "But it validates their claims that the killings were racially motivated and that something could have been done to have prevented these incidents from ever occurring."

Means said workers at the plant had brought Williams's conduct to the company's attention, and Lockheed sent him to anger management classes. Among other things, Williams once wore a Ku Klux Klan hood to work, according to Means, and brought unconcealed weapons into the building the morning of the shooting.