HELP ON IPHOTO! lost photos! recovery?

I shot 450 pictures today at an event, including family photos. Transferred the photos from the SD card directly into iPhoto - made two files of the ones I liked best, (one in black and white) then this white screen box pops up and says it unexpectedly quit. I go back into Iphoto and ALLL my photos are gone. I checked the Trash. HOW am I going to tell my sister I somehow trashed her son's photos? I'm in FULL panic mode. Then i remembered the D7100 has a backup SD card. Whew! I'm back in the family

TL, are the original images still on the SD card?

I never format my SD card until I make sure it's in the computer, plus on the external HD backup, plus uploaded to Flickr.

But you need to tell what role that second card plays. Just because it's in there doesn't mean it acts like a backup. I have mine set as an overflow.