(Hypothetical) 6ft hardened-steel cube dropped at 100 meters

[DdraigiSun]

During a random conversation with a friend, we got onto the subject of dropping a 6ft cubed cube of Hardened-Steel from the height of 100 meters.

I ended up getting really curious about the energy it would cause, as well as the potential impact/destruction it would cause on the area.

Considering the large weight of the object I'd imagine it'd have a decent result, however, because I'm not particularly great with this stuff I thought that I'd ask people who are actually good at Physics.

 

[Nugatory]

You can work this out for yourself. You know the volume of your cube and google will find you the density of steel; this gives you the mass. The energy in Joules released by a mass $m$ falling from height $h$ is $mgh$. You can compare that with the energy per kilogram released by by various explosives (again, google is your friend) to get a sense of just how destructive the impact might be.