sands are running out

There is a limited amount of time before something happens. The phrase refers to an hourglass, in which sand trickles from the top of the hourglass to the bottom through an opening until it has run out. The sands are running out—if she doesn't move out of that neighborhood, she'll be the next victim of a violent crime. I know that picking a college is a big decision, but the sands are running out.