How can I recover missing videos from iphoto after a power outage?

I uploaded 40 home videos from my camera to iphoto. It said the import was succesful and asked if I wanted to delete them from the camera. I said yes. I then watched several of the videos in iphoto. They were all visible under the "last import" tab. While I was watching one of the videos, my power went out. When I restarted the computer and opened iphoto, the videos were no where to be found. The "last import" tab now shows the previous import I'd done last week, but none of the videos I uploaded today. If I scan through my Events, there are event entries for each of the dates of the videos, but no video files (the event folders for those dates are empty). How can I recover them? I do have Time Machine backing everything up automatically but I've never accessed it before and don't know where to start. Thanks!