Oh, this gives a lot more info that has not been available before. Slightly dubious it is from The Sun but assume they have the info from a reliable source?If the story is true, then it could give credence to one of the sisters accidently falling into the water - hence the screams.
There are residential properties over the road from the boathouse, so presumably someone from one of these houses heard the screams.
It does seem odd that the landlord reported them missing the same day they disappeared. Surely adult women are able to be away for a whole day, even missing a work shift, without that raising immediate concern?? I can’t imagine the landlord would be checking in on them daily??
The article does seem to hint they intentionally entered the water. An accident is of course plausible but surely there is no reason whatsoever 2 ladies would be in that area alone at that time in the morning.