I am not an expert on this plant, Trachelospermum jasminoides, but it is not dead. It could be something fungal, or, let's hope, it has just been severely chilled. Did you have a particularly cold winter? If so it will probably be ok in time. Another possibility is some sort of fumes/heat. My lemon looked similar when it got placed beside the shower room extractor outlet. Is there anything like that around? Just some possibilities. I'd go for the chill option if pushed.

Our winter was very cold this year - freezing rain and much more snow that usual. Maybe that is it. No fumes to speak of. Crazy thing, though, is everything else in my yard (and my neighbor's yard) is growing very well. All of our vines are happy except the jasmine (clematis, honeysuckle, aquebia quintana).

Emmettdigger, I'm wondering if your jasmines did recover? I have two jasmines that look similar to your pics and am debating whether to pull them out or give them a bit longer.

Thanks,
Deanna