Decent of the Iron Block

you summon a strange magical cube from an unknown dimension that resembles an iron block into the material realm and let it fall to the earth where it then disappears 1 second after impact. You pick a space within 60ft of you. A 10 by 10 cube appears 30ft above that space and then plummets to the earth. Any creature that was in the air within the blocks descent is knocked to the ground. All creatures within the area of the blocks decent and impact must make a strength saving throw. On a failed saving throw a creature takes 8d6 bludgeoning damage and is knocked unconscious. On a successful saving throw a creature takes half damage and is knocked prone but is not knocked unconscious.  

A creature that is knocked unconscious by this spell can make a constitution saving throw and the start of each of there turns. Upon a successful throw the creature is no longer unconscious. 

At Higher Levels. When you cast this spell using a spell slot of 6th level or higher, the range will increase by 30ft for each level above 5th and the area effected will increase by 10ft for every level above 5th.  Additionally the damage will increase by 1d6 bludgeoning damage for every level above 5th.