Three men believed to have been trapped in a massive explosion at an Illinois industrial plant warned others to leave the building before the blast, officials believe.
Three people have so far been confirmed dead after the explosion Friday night at AB Specialty Silicones in Waukegan, about 40 miles north of Chicago.
One person died of their injuries in a hospital, two bodies have been recovered from the scene of the blast and one person is still missing, authorities say.
Waukegan Fire Marshal Steven Lenzi told reporters Sunday that some of the nine workers in the building when the explosion occurred alerted their colleagues beforehand.
"From the information we have, some of the plant personnel -- especially those that are still missing -- alerted others to the issues going on shortly before the incident. At this point we have determined they did help people get out of the building," Lenzi said.
AB Specialty Silicones confirmed that the men who did not escape had been actively making products at the time, CNN affiliate WLS reported.
Lenzi said all nine employees affected had been working at the plant Friday night. Three survivors had been treated in area hospitals with moderate to serious injuries, while two others were seen but requested no treatment.
Lake County coroner Dr. Howard Cooper said there was little information he could give on the deceased: "We're not giving out any names at this time. We actually don't do anything to determine who they are at this point in time -- we'll do that tomorrow (Monday). I can tell you that we will be using dental records for at least one of them for sure."
Not looking at 'foul play'
The search for the one person still unaccounted for will resume at 9 a.m. local Monday, Lenzi said.
No cause for the explosion has been determined yet. The fire chief told reporters the investigation into the incident was ongoing and that plant personnel were still being interviewed but had been helpful.
"It is an accidental cause, we are not looking at any foul play," Lenzi said, without elaborating.
One person was found dead at the scene Saturday, Lenzi said. Authorities weren't able to continue any further recovery efforts until they brought in equipment to dismantle the "heavy unsafe structural remains."
"Today (Sunday) we have had our technical rescue specialists. These are guys that are really digging into to the nooks and crannies safely to search and in their search efforts today they were able to locate one of the other victims."
The second body was located in "a heavily damaged portion of the building," according to a statement from the Waukegan Fire Department. "Due to the complexities of removing the victim from the debris it took crews over two hours" to recover the body, the statement said.
Damage from the explosion is estimated at more than $1 million, Lenzi said earlier. The blast affected at least five other nearby buildings.
Cmdr. Joe Florip, a Waukegan police spokesman, said he would "categorize this as a massive explosion."
"Many neighboring properties are going to have damage," he said.
After the explosion, the Lake County Sheriff's Office said on Twitter it was aware of "a very loud explosion sound" and "ground shaking."
CNN affiliate WLS reported that some debris was found miles from the plant.
"You could just feel the walls shake. It was almost like a sonic pulse. Luckily, I didn't have any windows broken out, but you could definitely feel it. It was unlike anything I've felt before," resident Tim Stevens told the station.