Is it dead?

I have a plant that is still vegging, early phase. The stem was thin in one spot from stretching but the problem was fixed and good stem grew in. now the top 1/3 of my plant just fell off even though it looked so nice.

I snipped down as much as I could of the dead stem. Does the lower 2/3 have a chance of surviving?

a chance but beter to start a fresh. main thing is to work out wot went wrong

1/3 is a lot to cut off a plant i dont like to cut nothing how tall is ur plant?