gasnuti

1. (of fire, light) to go out; to die down
   Vatra u kaminu polako gasne. — The fire in the fireplace is slowly dying down.
   Svetla u gradu gasnu jedno po jedno. — The lights in the city go out one by one.
2. (of hope, life, feelings) to fade; to wane
   Nada da ćemo ga naći polako gasne. — The hope of finding him is slowly fading.
   Njegov interes za školu gasne iz dana u dan. — His interest in school is fading day by day.

Do not confuse with gasiti (to put something out): gasnuti means to go out by itself; a completed event is usually expressed with ugasnuti. For an engine or car stalling, gasiti se is the usual choice: Auto mi se stalno gasi na semaforu.