San Bernardino County Fire Department responded to a reported commercial structure fire at 885 N D St. Arriving crews located the front door of a business that had been lit on fire and the door smashed in. Upon further inspection an illegal marijuana grow operation was discovered. SBPD was dispatched to the location and one subject was taken into custody. Arson investigators are on scene handling their part of the investigation while PD is investigating the marijuana grow. The marijuana grow was located inside what appeared to be a church building. The entire inside of the location was filled with marijuana plants and high pressure sodium lighting with equipment that would draw a lot of power. It's unknown whether electricity was being stolen at the location as well to power all the equipment. The cause of the fire or the reason it was lit is unknown and under investigation.