What do all the guest do when the groom or the bride doesn’t show for their wedding leaving the future spouse hanging in the breeze?

If the groom is a no-show, or the bride ditches the wedding, what will everyone do? They might have traveled far to get there, rearranged schedules, altered plans, got all dressed up, and now there is no event, what do they do, say sorry to the person dumped at the altar and high tail it out of town, use the occasion to have a mini vacation, what do they do?