There’s only two directions out of town north and south east is where the fire was. The southbound road was reportedly impassable at a point due to falling debris, the northbound road eventually becomes one narrow winding lane. It’s highly unlikely any of those side roads would go anywhere.
Sounding sirens likewise would have done no good, when the power and water were gone and the wind howling for hours, that was the alarm. The whole town was in panic mode and leaving then.