I planted few sugar snap beans few weeks ago and unfortunately there was heavy rains for 2 weeks continuously. Now my young plant have leaves disappeared, not sure because of the rains or any pests/bug who ate the leaves?
My experience with any foliage disappearing is that there are bugs somewhere. I can't rembember losing leaves to rain, and it rains a lot where I live. I would dig around carefully and also examine the plants thoroughly to see if I could find a suspect or two. Maybe somebody else on here has a more plausible explanation.
Wow! Totally denuded! I've never had that happen, or rather happen as badly as that! I agree with others, it's probably bugs of some kind. The leaves may very well regrow. You could also just plant another row & watch them carefully. A lot of gardening is simply watching what's happening. You know, keeping an eye on things.
Where are you located? That can help sometimes. My slugs do go underground during the day. I almost never see them, but when I see their damage I put out slug bait. The can denude a plant like that, almost overnight. I guess those are sugar snap peas and not beans? Probably same answer either way.
Outgoing, if you determine slugs are your problem, there is a pretty easy solution. Get some mason's sand (it has more silica than the play sand) and spread it around your plants. The silica cuts the slugs' tummies open. There are few better sights in the morning than a bunch of dead slugs!
I had something similiar but with a different vegetable. Just under the cover of the soil I found about five caterpillers. They would come out at night and munch away, leaving nothing but the stalk. BTK would have taken care of it had I not found the little munchers. In my experience with slugs, there is often some kind of a slimy/shiny trail. For me they also aren't as efficient about completely denuding a plant of it's leaves. The caterpillars voracious appetitie can make short work of tender leaves. Good luck!