Possible Clues:

• In an emergency, weep little sister, by the sound of it (6)
• Weep, little sister, if this has you in a sorry state
• Moment of danger
• Cause for a Security Council emergency meeting
• Weep, little sister, at this crucial point
• Situation of extreme danger
• Climax point in, say, a fever
• By the sound of it, weep, Sister, for the emergency
• Being a piece of potato short is a disaster
• Big pickle?