IPhoto 'quit unexpectedly' and an entire recent import disappeared

Question

About an hour ago, I imported around 100 photos from a boat trip this morning from my camera onto iPhoto. They imported quickly, as per usual, and I selected the option to delete the photos on the camera, having had no issues with iPhoto so far this holiday. I looked through them all and even edited a few.
The next time I opened my laptop (about a minute ago), a slideshow of the recent photos began running, which was strange as my laptop was locked. I pressed esc a few times until the password interface came up and then logged in. A error message came up saying iPhoto had quit unexpectedly, I pressed ignore and then reopened it. I noticed an empty event from today (18th April) and after checking quickly, realised all the photos I had just imported had completely disappeared. I checked the iPhoto trash, and they weren't there, and my laptop trash (no surprises, they weren't there either). It was basically like I had never imported them, apart from the empty event.
This really *****, because I don't have any back ups and there were some really great pictures in there. Is there any way I can recover them?

Answer 1

I selected the option to delete the photos on the camera
As you know now never have iPhoto delete the photos.  Do it in the camera by reformatting the memeory card after you've verified the photos are in the library and can be viewed and edited OK.
That being said apply the two fixes below in order as needed: 
Fix #1
Launch iPhoto with the Command+Option keys held down and rebuild the library.
Since only one option can be run at a time start with Option #3, followed by #4 and then #1 as needed.
Fix #2
Using iPhoto Library Manager  to Rebuild Your iPhoto Library
1 - download iPhoto Library Manager and launch.
2 - click on the Add Library button, navigate to your Home/Pictures folder and select your iPhoto Library folder.
3 - Now that the library is listed in the left hand pane of iPLM, click on your library and go to the File ➙ Rebuild Library menu option.
4 - In the next  window name the new library and select the location you want it to be placed.
5 - Click on the Create button.
Note: This creates a new library based on the LIbraryData.xml file in the library and will recover Events, Albums, keywords, titles and comments.  However, books, calendars, cards and slideshows will be lost. The original library will be left untouched for further attempts at fixing the problem or in case the rebuilt library is not satisfactory.
If the above doesn't do the trick, you have a camera with a memory card (not a smart phone) and you haven't used the camera since then and haven't reformatted the memory card with the camera you can use  MediaRECOVER to recover the photos from the card.  You can use it in demo mode to verify it an recover the photos you're interested in before you purchase it.
OT