Are they in the last import?
A very common issue is the camera date/time being set incorrectly or the event sort (view menu ==> sort events) being incorrect
BTW it is strongly recommended that you never have any computer program including iPhoto delete your photos - after importing keep the photos and then after at least one successful backup cycle you can use your camera's format command to reformat and erase the memory card - personally I rotate between three large cards so I do not delete the photos from my memory card for a year or more
I am so sorry Larry, I went to sleep shortly after I posted.
iPhoto nor the system crashed. I did download the pictures several times before they showed up on iPhoto though. I lost the pictures the following day.
As an update, i was able to retrieve the pictures. I was going through each tab when I stumbled upon the File tab and I pushed "switch to library." Here it showed 3 different iPhoto libraries that I had. I was then able to find the pictures I was searching for. Rest assure, I am making sure that I make several copies before I try to import them to my original iPhoto library.
I do thank you for your time and help.