Updated at 9:33 a.m.

Search and rescue personnel have located and recovered the body of a third employee killed in the explosion and fire at an Illinois silicone plant. Waukegan Fire Marshal Steve Lenzi told a news conference that the body was located Sunday afternoon. In addition to the three confirmed dead, officials believe a fourth body remains in the rubble.

An explosion at a factory on the edge of far north suburban Waukegan is believed to be an accident, authorities said.

One victim, who has not been identified publicly, was found in the rubble of the plant, and another worker who was injured in the blast died at a hospital on Saturday, officials said.

Allen Stevens, 29, of Salem, Wisconsin, died at Loyola Medical Center in Maywood at 11:50 a.m., according to a spokeswoman for Cook County’s medical examiner. Stevens was taken first to a hospital in Waukegan and later transported to Loyola.

The cause of the explosion at AB Specialty Silicones was not yet known, said Waukegan Fire Marshal Steven Lenzi, although investigators had no reason to suspect foul play.

“We do have some good leads we are working,” Lenzi said Saturday morning as he stood near the charred shell of the factory, soon after rescuers recovered the body of one factory worker. “At this point, it appears to be all accidental.”

Yellow tape surrounded the site, and the search for the other two missing workers was delayed, Lenzi said, because what is left of the factory’s structure is unstable and it would be too hazardous to resume looking for the bodies now.

Large chunks of metal debris and wisps of insulation material were scattered hundreds of yards from what had been a 30,000-square-foot facility at Sunset and Northwestern Avenue. The blast was so powerful it knocked down a road sign across the street.

Authorities say there were nine workers in the factory when the explosion occurred at about 9:30 p.m. Friday. Four were taken to hospitals in Waukegan and Libertyville, and two other employees emerged from the blast without injuries.

The explosion was felt miles away from the factory, which is located at the northwestern edge of the city in Lake County, about 40 miles north of Chicago.

Marely Sanchez, who lives close to the factory, said her husband was at home and taking a shower when the impact of the blast nearly knocked him down.

“It sounded like a bomb, honestly,” she said. “It looked like fireworks. The house shook. All of our paintings fell. It was awful.”

According to the website for AB Specialty Silicones, the company makes “silicone-based ingredients” for use in the production of hair and skin care products.

— The Associated Press Contributed to this report.

Dan Mihalopoulos is a reporter for WBEZ. Follow him at @dmihalopoulos.