Is one branch of the yellow flowered plant broken off? Could be cats, could be anything / anyone who may have brushed past and bent the branch too far so it broke partly through. I've known them break in wind too, though usually more than one if it's windy.

Oh dear, what a shame.....yes it could be cats or something eating the roots?

The drooping yellow flowers are certainly at spraying height for a cat. Sorry to be indelicate, but you can tell by the smell if a cat was responsible.

thanks all for the info,i suspected cats,but as Oj93 pointed out the first bit of detective work was with my nose, but there was no apparent smell? Don't think thers is anything attacking the roots as the rest of the pot is healthy. The plant is a mini petunia and it is not the first one i've lost, about 3wks ago in a different pot lost 1 too, but that space got overtaken by the geranium,so the effect was not lost,so the local felines must be guilty??

Not sure I'm convinced its a cat - male cats spray at that height, neutered toms tend not to bother, and females don't, they squat. And when a male cat sprays, your nose tells you its happened.

Normally, cat spray would cause some of the branches of a plant to turn instantly brown, with scattered brown spots on the leaves around the dead area. Very little wilting would occur. It looks like an entire plant has died, which would make me suspect collar rot, which petunias, especially the yellow kinds, are very susceptible to.

Would agree, I don't think that's cat damage. Either rot or stem broken - unless you have some vine weevils in the pot, in which case watch out for it happening to another of the plants.