Deleting individual indexes from a datastream

I have a datastream which I set up recently and as a check I set to rollover every day so I could see that it was woking as expected. That was just before Christmas and I saw it roll over once...

I came back today and found that as soon as I turned my back there was an issue with the data source and I now have 5 empty indexes taking up valuable shards. When I try and delete these kibana warns me that "deleting system indexes may break things". Clearly this is true for real system indices but is it still true for datastream indices>

Can you post a screenshot of that?

sorry to take so long -- I have been trying not to work during my "holiday"!