Fire and Rescue NSW (FRNSW) crews have battled explosions and large blaze in a vehicle scrap yard at Trenayr, north of Grafton, in the state's northern rivers district.More than 15 fire trucks responded to the emergency in Trenayr Road, just before 6pm. The fire took hold in rows of scrapped cars, stacked up to 10 vehicles high, and sent a large plume of black, toxic smoke into the sky.A firefighter received a head injury whilst fighting the blaze. She was admitted to hospital for observation an