Authorities say seven northern Georgia first responders have been hospitalized after being exposed to an unknown substance while at a crash. Gilmer County Public Safety Director Keith Kucera says Fire Rescue units were sent to the single-vehicle crash Thursday evening, where the responders found a pickup truck that had hit a tree. The emergency crews treated the two people who were in the truck for trauma-related injuries. Two sheriff’s deputies and five emergency medical services workers suffered exposure symptoms to what authorities called an unknown controlled substance that was in the vehicle. They were all taken to hospitals for treatment and have since been released.