A small 10 kiloton warhead would devastate the target area or wherever is goes off. However - the blast effect will not radiate more than a mile or two. Majority of population will survive the blast. Problem will be if it hits close to Honolulu Harbor it will knock out our port facilities. Food and water (for drinking and sanitation) will become priorities when this happens. You don't have to be a prepper to follow the recommendation and keep sufficient food and water on hand to keep your family going for at least two weeks.
YMMV