KENT COUNTY, Mich - Authorities are warning people about a potentially explosive technique that is used to make a powerful marijuana concentrate following an overnight fire in Grand Rapids.
Grand Rapids Police say hash oil extraction took a dangerous turn at a home along Sigsbee Street, leaving one person with critical injuries.
The homeowner says he has a card to grow medical marijuana, which is something investigators say they're working to verify.
But whether or not the card makes the grow operation legal, it's the extraction of THC using butane that could lead to felony charges.
FOX 17's Christian Frank has more in the video player above.