Huh? The speed of sound is only ~720mph at sea level (would travel about 85 miles in 7 minutes).
Whoops never mind... hours, minutes, what's the difference? =)
Then how could a metorite which SLOWED to 720 mph to make a sonic boom and burn up to a point where they can't even say if any of it made it to the ground do any damage like a nuclear bomb at Hiroshima? Shouldn't northern Norway be devasted? Miles of trees blasted into toothpicks and villages vaporized?