Helicopter crashes into crane in London

[mtnester]

4. I am curious if the crane had a warning light on the top

this accident would make more sense (as far as cause...no accident makes sense when folks are hurt or die) if it did not and it was morning low light with any kind of drizzle or fog...if this was a normal path for this helicopter, and someone suddenly put up a 4 story stick (guessing on height, could be bigger or smaller) without a warning beacon and visibility was poor due to time of day or weather conditions, what could go wrong?