Search and recovery personnel found the body of another worker Sunday in the rubble of a northern Illinois silicone factory that exploded and burst into flames two days earlier, bringing the death toll to three employees with one more body believed to be in the debris, a fire official said.

Waukegan Fire Marshal Steve Lenzi said the body was found as first responders resumed searching in hazardous conditions in the shattered remains of the AB Specialty Silicones plant in Waukegan, about 50 miles (80 kilometers) north of Chicago.

They were searching for the bodies of two of the nine workers who were there when an explosion rocked the building Friday night and left it a shattered skeleton.

"We are in the process of removing one of those two bodies," Lenzi told a news conference Sunday. He said at least half of the building still needs to be searched.

SECOND DEATH REPORTED AFTER CHICAGO-AREA PLANT EXPLOSION

Of the nine in the building at the time of the blast, one body was found early Saturday. Four people were taken to the hospital and one of those died later Saturday. The condition of the other three workers in the hospital was not immediately known, Lenzi said. The third confirmed death was the body located Sunday with one other body still to recover. Two other workers did not require treatment at the time.

The cause of the explosion hasn't been determined, although Lenzi said it originated in the building where the silicone is produced.

"Most of the processes that they do are very non-hazardous. Silicone itself, not a hazardous substance," Lenzi said. "Something ... this weekend went horrifically wrong."

AB Specialty Silicones makes specialty silicone chemical raw materials for products such as adhesives, sealants and coatings.

BUILDING 'LEVELED' IN EXPLOSION THAT ROCKS CHICAGO SUBURB

Lenzi said authorities have concluded that the explosion and fire was accidental.

"We are not looking at foul play."

Lenzi said that from information they have gleaned in the preliminary investigation, some of the employees realized something was wrong and alerted others to get out of the building just before the explosion.

Lake County Coroner Howard Cooper said that his office would perform autopsies Monday on at least two of the bodies and would announce the names of the victims and preliminary causes of death. Dental records would be used to identify at least one of the deceased, he said.