HOPKINTON - We’re learning more about the tractor-trailer fire Monday night along I-495 near Hopkinton. Fire officials say while people reported hearing explosions that was likely the sound of the tires exploding and not anything inside the truck, with the trailer actually empty at the time. The truck fire did catch several trees on fire along the side of the road but multiple fire crews responded and knocked it down. There is still no cause reported for the initial truck fire. Fire officials say the driver was not hurt nor was anyone else.