By Tara Molina

CHICAGO (CBS) — A deadly explosion 90 miles southwest of Chicago at Starved Rock State Park.

Three men died along the bank of the Illinois River. CBS 2’s Tara Molina reports, police believe black powder sparked the blast.

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First responders rushed to this section of the Illinois River bank near Starved Rock State Park, where the LaSalle County Coroner’s Office said three men were found dead.

They say the men ignited a black powder here causing the explosion, then died from their injuries.

With investigative autopsies scheduled Friday, the coroner is holding off on identifying those men until they’re able to get in touch with their families. We know the FBI responded, but a spokesperson said it is not commenting on this case.

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CBS 2 also checked in with the Kane County Sheriff’s office, since its bomb squad responded to the explosion. It’s deferring to Illinois State Police, leading the investigation here.

But state police aren’t saying much, only that this is active and isolated, with no public safety concerns right now.

The coroners office said the incident is “not related in any way to the recent demolition of the old 178 bridge,” but with that project continuing now, with park evacuations for demolition, CBS 2 asked ISP if the black powder could have been a substance used in the project. ISP wouldn’t address that question with the investigation ongoing.

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The three men still haven’t been publicly identified. CBS 2 was told to check back for more information on this investigation next week.

Tara Molina