I'm surprised that they couldn't reschedule the flight in a few hours. That plane has a schedule for a few days, meaning there is a flight waiting on its arrival. So, what happened with the flight that was supposed to move on (or back) with that plane. It must have been canceled as well, which means more passengers cancelled as well. There are crews who are listed as standby to be able to fly on a few hour's notice, so unless the plane had something happen to take IT out of service, for days, they could fix this plane and have another flight crew that is on standby take over the flight.