Away from Europa, I think it's maybe unfair to say other parks would not have opened. Most would after an incident as long as it's safe to do so, afterall they have guests who've made travel plans etc. The incidents at Drayton and Alton are different as people were severely injured or killed, meaning you've then got the PR tightrope to walk on whether it is morally right to reopen along with safety checks/investigations where necessary.
It makes me so sad seeing that footage. The juxtaposition of beauty and destruction.
Don't suppose anyone who knows a bit of German is able to give a summary of what the park officials were saying?
Is there any indication of what started it yet? Probably too early to tell, or even if they have and idea, they might not say until furher investigations are made. But it's worth asking.