A Chicago woman called the police after witnessing a cache of disturbing material inside an apartment where she was working on an HVAC service at the building.

"I came across some C4, some explosives, a rifle, a lot of fake IDs, a lot of fireman stuff, a lot of police force stuff and a lot of it looked like it was fake, you know?" HVAC employee Melissa Carraway told ABC 7.

She added, "There's a suitcase with explosives that said 'C4' and I googled the pictures. Looks like military stuff. I saw a big rifle by a window. I said I'm going to call the police."

"You know the bombing that happened in New Orleans and then in Vegas, so it kind of scared me" Carraway explained.

A person was taken into custody by police at the scene, but the man has not been charged with any crimes at the time of this article.

According to a WGN Investigates source, the suspect was previously fired from the Chicago Fire Department in 2022 and threatened to commit a mass shooting.

The incident takes place as the FBI warns of "ISIS-style vehicle attacks" copying the New Orleans New Year's Day rampage.