War of the roses

Hi all. I'm having a problem with my roses this year and I'm not a rose expert so would appreciate some help. I planted a new rambler - bare root - last autumn. It started growing really well in the spring, sent up several shoots and got to a foot high in no time. Then, suddenly, for no apparent reason, it just died. All the leaves turned brown and curled up, most of the stems have gone dark brown, and died. I've cut back all the dead bits and am left with 3 or 4 green stalks without any leaves. How can I help it thrive again?