Mother/father/wife/child rushed to hospital.

Small children are great for that - sick/throwing up all night, swallowed a coin etc. Of course depends on if you have one or not.

A bad crick in the neck is a good one, especially if you turn up the next day with a foam neck brace of some description.

Or real killer - dog/cat hit by car, rushed to vets, but not much that they could do. You are really cut up about it...