What could cause a 60 year old to suddenly lose control of her bladder?

Various things: Leakage of urine can occur due to bladder infections, prolapse (loss of support for the vagina and bladder caused by damage to the supporting tissues of the pelvis), and malfunctioning nerves which control the bladder. There are other less common causes, including trauma, surgical injury, cancer, but these usually will be associated with other symptoms. An exam and physician evaluation is needed.