A 28-year-old man was arrested and James Caldwellcharged after authorities discovered "improvised explosive devices in a makeshift laboratory" at his Philadelphia home, officials announced on Wednesday.

According to a press release from the Philadelphia District Attorney's Office, members of the local fire and police departments responded to a fire at a rowhome in the city's Mayfair neighborhood Friday night.

Smoke was emerging from the garage and inside the home. Residents in the area were ordered to evacuate.

The man, identified as Evgenii Sadrislamov, and his mother were escorted outside of the home while authorities executed a search. Officials determined the property was a hazmat scene.

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Materials found could have 'leveled the entire block': officials

Homeland Security and ATF arrived at the scene to help with the probe. According to the DA, they discovered an estimated 50 pounds of explosives.

"Upon obtaining a search warrant, investigators recovered several improvised explosive devices as well as explosive powders from a bomb-making laboratory located in the basement and garage," the press release stated, adding: "Investigators believe that if this material had ignited, it would have leveled the entire block of homes."

Sadrislamov is facing several charges, including weapons of mass destruction, arson, possession of an instrument of crime, and causing catastrophe. He is being held on $1 million bail.

Fox 29 reported that the suspect has a criminal history, noting he had commercial-grade fireworks in the residence back in 2020. He was placed on probation.

"Investigators and our partners at ATF bomb squad and Homeland Security all agree that there has been a clear escalation in the sophistication and scale of the operation in which this defendant had been possessing and throughout the years," Assistant District Attorney Angela Brennan said at a news conference posted by the outlet.

Taylor Ardrey is a news reporter for USA TODAY. You can reach her at [email protected].