A factory worker known as a racist "hothead" who talked about killing people opened fire with a shotgun at a Lockheed Martin (search) plant Tuesday, leaving five fellow employees dead before committing suicide.

Dozens of employees at the aircraft parts plant frantically ran for cover screaming "Get out! Get out!" after Doug Williams, dressed in a black T-shirt and camouflage pants, started firing. The rampage occurred after Williams attended a meeting on workplace ethics.

Nine people were injured, including one critically, in the nation's deadliest workplace shooting in 2 years.

"At first I thought it was something falling on the ground. Then I walked to the aisle and saw him aiming his gun. I took off. Everybody took off," said Booker Steverson, who was helping assemble airplane parts when he heard the first shot.

Exactly what set Williams off was not immediately clear, but co-workers said the 48-year-old assembler had had run-ins with management and several fellow employees.

"Mr. Williams was mad at the world. This man had an issue with everybody," said co-worker Hubert Threat. "It's not just about race. It was just the excuse he was looking for."

Williams was white, and four of his victims were black; the fifth was white.

Nevertheless, Sheriff Billy Sollie said it appeared Williams fired at random. "There was no indication it involved race or gender as far as his targets were concerned," Sollie said.

Several co-workers said they were not surprised when Williams was identified as the killer.

"When I first heard about it, he was the first thing that came to my mind," said Jim Payton, who is retired from the plant but had worked with Williams for about a year.

Steverson said Williams was known as a racist who did not like blacks. And Payton had said Williams had talked about wanting to kill people. "I'm capable of doing it," Payton quoted Williams as saying.

One of those killed was Lanette McCall, a black woman who had worked at the plant 15 years. Her husband, Bobby McCall, said she expected Williams to harm someone someday.

"She said he made a threat against black people," a distraught McCall said. He added: "Obviously, he was a sick guy. I wish somebody had given him some help before he done destroyed my life and my kids' life."

Russell Wright, who works at the plant but was not there Tuesday, described Williams as "a hothead."

The sheriff said he had no information on whether the gunman had been in trouble with his bosses. Williams and other employees were attending an annual ethics meeting that the company requires of all its workers. Most of the victims had attended the meeting, authorities said.

"We are not sure if those killed were friend or foe," the sheriff said.

Austin Clark, who called in sick Tuesday, said Williams made accusations when he was angry. "He's had problems with white people, too," said Clark, who is white. "I have no idea what set him off."

Authorities said Williams was carrying a .223-caliber semiautomatic rifle when he entered the plant, but he apparently only used the 12-gauge shotgun. He also had three other guns in his truck.

Law officers made vehicles go through checkpoints outside the plant at midday as about two dozen people waited to learn the fate of their loved ones.

Some of the wounded were hospitalized in critical condition.

The shooting stunned residents of Meridian (search), a city of 40,000 near the Alabama line whose economy is largely dependent on the military. It is home to the Lockheed plant, a naval air station and an Air National Guard (search) training center.

"We know one another, almost everyone knows someone who works in the building, or has a relative who works in the building," said Craig Hitt, president of the Lauderdale County Board of Supervisors.

The Rev. Kathy Spells pleaded for racial unity the city mourns its losses. "It's time to get together and pray and get this racist thing over with," Spells said.

The Meridian plant employs about 150 people and builds parts for C-130J Hercules (search) transport planes and vertical stabilizers for F-22 Raptor (search) fighter jets.

Dain Hancock (search), president of Lockheed Martin Aeronautics, called the shootings "a horrible tragedy, a senseless crime."

"There are no words that can express the amount sorrow that has been felt by all of those who have been touched," Hancock said.

Lockheed Martin is the biggest defense contractor in the United States. The corporation had sales of $24 billion in 2001. It employs about 125,000 people.

Gov. Ronnie Musgrove (search) said: "Mississippi's family grieves today for this senseless tragedy. My thoughts and prayers are with the families and friends of those lost."

It was the nation's deadliest workplace shooting since a software tester in Wakefield, Mass., killed seven people the day after Christmas in 2000.

The dead were identified as Lanette McCall, 47, of Cuba, Ala; Micky Fitzgerald, 45, of Little Rock, Miss.; Sam Cockrell, 46, of Meridian, Miss.; Thomas Willis, 57, of Lisman, Ala.; and Charlie Miller, 58, of Meridian, Miss.