Well if you wait long enough it is just possible the answer will show up.
Why were there six empty cigarette cartons on the tow path this morning?
Not much evidence to go on, but the time. I went out about ten it had been raining an hour before. All the cartons were wet. The cartons arrived before nine. What happens around nine? School starts!
There are some houses across the bridge and as I noticed this afternoon the lads use the towpath to travel to and from school. It could be that the tow path is the first place they would light up on their journey. I will have a quiet chat with the lads in the morning.