Pansies

Almost overnight my Pansies have flopped over and are dieing, it looks as if they need water but that is not the case, I have got a lot of pots and they are all getting affected the same way I can not make it out as they were flowering and so healthy, any ideas would be helpful 

Have you inspected the roots?  It could be that they have been waterlogged, even though you say they look as if they need water.  Waterlogging would cause the roots to rot.

The other possible culprit is the dreaded vine weevil - the grubs, which look like white "C" shapes with a brown head, eat the roots, and plants will suddenly keel over.

Thanks I am going to have alook