As an additional follow on from Destruction by design - how best to go about crafting a ruined landscape? I'm asking some questions about signature destructive patterns. This is the second one, the first follow up deals with deliberate demolition type destructive processes and can be found here:
This question is about the ruins of war. Now, obviously we have a lot of good data about what most of our modern arsenal does to buildings, so I'd like to look at the use of orbital weapons and in particular energy weapons. What, if any, kind of diagnostic patterns of damage might we expect to see in a ruined city that has been subjected to heavy bombardment using space based energy weapons?
I feel that this should be answerable without excessive conjecture in light of the damage profiles of modern thermal cutting tools like industrial lasers and plasma cutters. anon's answer has pointed out that I should have made a note that the weapons are tactical rather than strategic in nature and as such they have a much smaller area of effect compared to nuclear or other weapons used to annihilate entire cities. In this case consideration needs to be given not only to reasonably fresh damage but also to how such damage may weather differently to conventional explosives with time. Please use the same 200 year benchmark as with the previous "Signature of destruction" question linked above.